Source code for pynq.ps

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import numpy as np
import os
import warnings
from .mmio import MMIO

__author__ = "Yun Rock Qu"
__copyright__ = "Copyright 2017, Xilinx"
__email__ = "pynq_support@xilinx.com"

ZYNQ_ARCH = "armv7l"
ZU_ARCH = "aarch64"
CPU_ARCH = os.uname().machine
CPU_ARCH_IS_SUPPORTED = CPU_ARCH in [ZYNQ_ARCH, ZU_ARCH]

DEFAULT_PL_CLK_MHZ = 100.0


[docs]class Register: """Register class that allows users to access registers easily. This class supports register slicing, which makes the access to register values much more easily. Users can either use +1 or -1 as the step when slicing the register. By default, the slice starts from MSB to LSB, which is consistent with the common hardware design practice. For example, the following slices are acceptable: reg[31:13] (commonly used), reg[:], reg[3::], reg[:20:], reg[1:3], etc. Note ---- The slicing endpoints are closed, meaning both of the 2 endpoints will be included in the final returned value. For example, reg[31:0] will return a 32-bit value; this is consistent with most of the hardware definitions. Attributes ---------- address : int The address of the register. width : int The width of the register, e.g., 32 (default) or 64. """ def __init__(self, address, width=32, debug=False): """Instantiate a register object. Parameters ---------- address : int The address of the register. width : int The width of the register, e.g., 32 (default) or 64. debug : bool Turn on debug mode if True; default is False. """ self.address = address self.width = width self.debug = debug if width == 32: self._buffer = MMIO(address).array.astype(np.uint32, copy=False) elif width == 64: self._buffer = MMIO(address).array.astype(np.uint64, copy=False) else: raise ValueError("Supported register width is 32 or 64.") def __getitem__(self, index): """Get the register value. This method accepts both integer index, or slice as input parameters. Parameters ---------- index : int | slice The integer index, or slice to access the register value. """ curr_val = int.from_bytes(self._buffer, byteorder='little') if isinstance(index, int): self._debug("Reading index {} at address {}" .format(index, hex(self.address))) mask = 1 << index return (curr_val & mask) >> index elif isinstance(index, slice): start, stop, step = index.start, index.stop, index.step self._debug("Reading bits {}:{} at address {}" .format(start, stop, hex(self.address))) if step is None or step == -1: if start is None: start = self.width - 1 if stop is None: stop = 0 elif step == 1: if start is None: start = 0 if stop is None: stop = self.width - 1 else: raise ValueError("Slicing step is not valid.") if start not in range(self.width): raise ValueError("Slice endpoint {0} not in range " "0 - {1}".format(start, self.width)) if stop not in range(self.width): raise ValueError("Slicing endpoint {0} not in range " "0 - {1}".format(stop, self.width)) if start >= stop: mask = ((1 << (start - stop + 1)) - 1) << stop return (curr_val & mask) >> stop else: width = stop - start + 1 mask = ((1 << width) - 1) << start reg_val = (curr_val & mask) >> start return int('{:0{width}b}'.format(reg_val, width=width)[::-1], 2) else: raise ValueError("Index must be int or slice.") def __setitem__(self, index, value): """Set the register value. This method accepts both integer index, or slice as input parameters. Parameters ---------- index : int | slice The integer index, or slice to access the register value. """ curr_val = int.from_bytes(self._buffer, byteorder='little') if isinstance(index, int): if value != 0 and value != 1: raise ValueError("Value to be set should be either 0 or 1.") self._debug("Setting bit {} at address {} to {}" .format(index, hex(self.address), value)) mask = 1 << index self._buffer[0] = (curr_val & ~mask) | (value << index) elif isinstance(index, slice): count = self.count(index, width=self.width) start, stop, step = index.start, index.stop, index.step if step is None or step == -1: if start is None: start = self.width - 1 if stop is None: stop = 0 elif step == 1: if start is None: start = 0 if stop is None: stop = self.width - 1 else: raise ValueError("Slicing step is not valid.") if start not in range(self.width): raise ValueError("Slicing endpoint {} is not in range 0 - {}." .format(start, self.width)) if stop not in range(self.width): raise ValueError("Slicing endpoint {} is not in range 0 - {}." .format(stop, self.width)) if value not in range(1 << count): raise ValueError("Slicing range cannot represent value {}" .format(value)) shift = stop if start >= stop else start mask = ((1 << count) - 1) << shift self._debug("Setting bits {}:{} at address {} to {}".format( count + shift, shift, hex(self.address), value)) self._buffer[0] = (curr_val & ~mask) | (value << shift) else: raise ValueError("Index must be int or slice.") def __str__(self): """Print the register value. This method is overloaded to print the register value. The output is a string in hex format. """ curr_val = int.from_bytes(self._buffer, byteorder='little') return hex(curr_val) def _debug(self, s, *args): """The method provides debug capabilities for this class. Parameters ---------- s : str The debug information format string *args : any The arguments to be formatted Returns ------- None """ if self.debug: print('Register Debug: {0}'.format(s.format(*args)))
[docs] @classmethod def count(cls, index, width=32): """Provide the number of bits accessed by an index or slice This method accepts both integer index, or slice as input parameters. Parameters ---------- index : int | slice The integer index, or slice to access the register value. width : int The number of bits accessed. """ if isinstance(index, int): return 1 elif isinstance(index, slice): start, stop, step = index.start, index.stop, index.step if step is None or step == -1: if start is None: start = width - 1 if stop is None: stop = 0 elif step == 1: if start is None: start = 0 if stop is None: stop = width - 1 else: raise ValueError("Slicing step is not valid.") if start not in range(width): raise ValueError("Slicing endpoint {} is not in range(0,{})." .format(start, self.width)) if stop not in range(width): raise ValueError("Slicing endpoint {} is not in range(, {})." .format(stop, self.width)) if start >= stop: count = start - stop + 1 else: count = stop - start + 1 return count
class _ClocksMeta(type): """Meta class for all the PS and PL clocks not exposed to users. Since this is the abstract base class for all the clocks, no attributes or methods are exposed to users. Users should use the class `Clocks` instead. Note ---- If this class is parsed on an unsupported architecture it will issue a warning and leave class variables undefined """ @property def cpu_mhz(cls): """The getter method for CPU clock. The returned clock rate is measured in MHz. """ return cls.get_cpu_mhz() @cpu_mhz.setter def cpu_mhz(cls, clk_mhz): """The setter method for CPU clock. Since the CPU clock should not be changed, setting it will raise an exception. """ raise RuntimeError("Not allowed to change CPU clock.") @property def fclk0_mhz(cls): """The getter method for PL clock 0. This method will read the register values, do the calculation, and return the current clock rate. Returns ------- float The returned clock rate measured in MHz. """ return cls.get_pl_clk(0) @fclk0_mhz.setter def fclk0_mhz(cls, clk_mhz): """The setter method for PL clock 0. Parameters ---------- clk_mhz : float The clock rate in MHz. """ cls.set_pl_clk(0, clk_mhz=clk_mhz) @property def fclk1_mhz(cls): """The getter method for PL clock 1. This method will read the register values, do the calculation, and return the current clock rate. Returns ------- float The returned clock rate measured in MHz. """ return cls.get_pl_clk(1) @fclk1_mhz.setter def fclk1_mhz(cls, clk_mhz): """The setter method for PL clock 1. Parameters ---------- clk_mhz : float The clock rate in MHz. """ cls.set_pl_clk(1, clk_mhz=clk_mhz) @property def fclk2_mhz(cls): """The getter method for PL clock 2. This method will read the register values, do the calculation, and return the current clock rate. Returns ------- float The returned clock rate measured in MHz. """ return cls.get_pl_clk(2) @fclk2_mhz.setter def fclk2_mhz(cls, clk_mhz): """The setter method for PL clock 2. Parameters ---------- clk_mhz : float The clock rate in MHz. """ cls.set_pl_clk(2, clk_mhz=clk_mhz) @property def fclk3_mhz(cls): """The getter method for PL clock 3. This method will read the register values, do the calculation, and return the current clock rate. Returns ------- float The returned clock rate measured in MHz. """ return cls.get_pl_clk(3) @fclk3_mhz.setter def fclk3_mhz(cls, clk_mhz): """The setter method for PL clock 3. Parameters ---------- clk_mhz : float The clock rate in MHz. """ cls.set_pl_clk(3, clk_mhz=clk_mhz) @classmethod def get_pl_clk(mcs, clk_idx): """This method will return the clock frequency. This method is not exposed to users. Parameters ---------- clk_idx : int The index of the PL clock to be changed, from 0 to 3. """ if clk_idx not in range(4): raise ValueError("Valid PL clock index is 0 - 3.") pl_clk_reg = mcs.PL_CLK_CTRLS[clk_idx] src_clk_idx = pl_clk_reg[mcs.PL_CLK_SRC_FIELD] src_clk_mhz = mcs._get_src_clk_mhz(src_clk_idx) pl_clk_odiv0 = pl_clk_reg[mcs.PL_CLK_ODIV0_FIELD] pl_clk_odiv1 = pl_clk_reg[mcs.PL_CLK_ODIV1_FIELD] return round(src_clk_mhz / (pl_clk_odiv0 * pl_clk_odiv1), 6) @classmethod def set_pl_clk(mcs, clk_idx, div0=None, div1=None, clk_mhz=DEFAULT_PL_CLK_MHZ): """This method sets a PL clock frequency. Users have to specify the index of the PL clock to be changed. For example, for fclk1 (Zynq) or pl_clk_1 (ZynqUltrascale), `clk_idx` is 1. The CPU, and other source clocks, by default, should not get changed. Users have two options: 1. specify the two frequency divider values directly (div0, div1), or 2. specify the clock rate, in which case the divider values will be calculated. Note ---- In case `div0` and `div1` are both specified, the parameter `clk_mhz` will be ignored. Parameters ---------- clk_idx : int The index of the PL clock to be changed, from 0 to 3. div0 : int The first frequency divider value. div1 : int The second frequency divider value. clk_mhz : float The clock rate in MHz. """ if clk_idx not in range(4): raise ValueError("Valid PL clock index is 0 - 3.") pl_clk_reg = mcs.PL_CLK_CTRLS[clk_idx] div0_width = Register.count(mcs.PL_CLK_ODIV0_FIELD) div1_width = Register.count(mcs.PL_CLK_ODIV1_FIELD) src_clk_idx = pl_clk_reg[mcs.PL_CLK_SRC_FIELD] src_clk_mhz = mcs._get_src_clk_mhz(src_clk_idx) if div0 is None and div1 is None: div0, div1 = mcs._get_2_divisors(src_clk_mhz, clk_mhz, div0_width, div1_width) elif div0 is not None and div1 is None: div1 = round(src_clk_mhz / clk_mhz / div0) elif div1 is not None and div0 is None: div0 = round(src_clk_mhz / clk_mhz / div1) if div0 <= 0 or div0 > ((1 << div0_width) - 1): raise ValueError("Frequency divider 0 value out of range.") if div1 <= 0 or div1 > ((1 << div1_width) - 1): raise ValueError("Frequency divider 1 value out of range.") pl_clk_reg[mcs.PL_CLK_ODIV0_FIELD] = div0 pl_clk_reg[mcs.PL_CLK_ODIV1_FIELD] = div1 @classmethod def _get_src_clk_mhz(mcs, clk_idx): """The getter method for PL clock (pl_clk) sources. The returned clock rate is measured in MHz. """ if clk_idx not in range(4): raise ValueError("Valid PL clock index is 0 - 3.") src_pll_reg = mcs.PL_SRC_PLL_CTRLS[clk_idx] return round(mcs.get_pll_mhz(src_pll_reg), 6) @classmethod def _get_2_divisors(mcs, freq_high, freq_desired, reg0_width, reg1_width): """Return 2 divisors of the specified width for frequency divider. Warning will be raised if the closest clock rate achievable differs more than 1 percent of the desired value. Parameters ---------- freq_high : float High frequency to be divided. freq_desired : float Desired frequency to be get. reg0_width: int The register width of the first divisor. reg1_width : int The register width of the second divisor. Returns ------- tuple A pair of 2 divisors, each of 6 bits at most. """ div_product_desired = round(freq_high / freq_desired, 6) _, q0 = min(enumerate(mcs.VALID_CLOCK_DIV_PRODUCTS), key=lambda x: abs(x[1] - div_product_desired)) if abs(freq_desired - freq_high / q0) > 0.01 * freq_desired: warnings.warn( "Setting frequency to the closet possible value {}MHz.".format( round(freq_high / q0, 5))) max_val0 = 1 << reg0_width max_val1 = 1 << reg1_width for i in range(1, max_val0): for j in range(1, max_val1): if i * j == q0: return i, j class _ClocksUltrascale(_ClocksMeta): """Implementation class for all Zynq Ultrascale PS and PL clocks not exposed to users. Since this is the abstract base class for all Zynq Ultrascale clocks, no attributes or methods are exposed to users. Users should use the class `Clocks` instead. """ DEFAULT_SRC_CLK_MHZ = 33.333 # Registers in the CRL "Namespace" CRL_APB_ADDRESS = 0xFF5E0000 IOPLL_CTRL_OFFSET = 0x20 RPLL_CTRL_OFFSET = 0x30 PL0_CTRL_OFFSET = 0xC0 PL1_CTRL_OFFSET = 0xC4 PL2_CTRL_OFFSET = 0xC8 PL3_CTRL_OFFSET = 0xCC PLX_CTRL_CLKACT_FIELD = 24 PLX_CTRL_ODIV1_FIELD = slice(21, 16) PLX_CTRL_ODIV0_FIELD = slice(13, 8) PLX_CTRL_SRC_FIELD = slice(2, 0) PLX_CTRL_SRC_DEFAULT = 0 PL_CLK_SRC_FIELD = PLX_CTRL_SRC_FIELD PL_CLK_ODIV0_FIELD = PLX_CTRL_ODIV0_FIELD PL_CLK_ODIV1_FIELD = PLX_CTRL_ODIV1_FIELD # Registers in the CRF "Namespace" CRF_APB_ADDRESS = 0xFD1A0000 APLL_CTRL_OFFSET = 0x20 DPLL_CTRL_OFFSET = 0x2C VPLL_CTRL_OFFSET = 0x38 ACPU_CTRL_OFFSET = 0x60 ACPU_CTRL_CLKHALF_FIELD = 25 ACPU_CTRL_CLKFULL_FIELD = 24 ACPU_CTRL_ODIV_FIELD = slice(13, 8) ACPU_CTRL_SRC_FIELD = slice(2, 0) # Fields shared between CRF and CRL "Namespaces" CRX_APB_SRC_DEFAULT = 0 CRX_APB_SRC_FIELD = slice(22, 20) CRX_APB_ODIVBY2_FIELD = 16 CRX_APB_FBDIV_FIELD = slice(14, 8) PLX_CTRL_ODIV1_WIDTH = (PLX_CTRL_ODIV1_FIELD.start - PLX_CTRL_ODIV1_FIELD.stop + 1) PLX_CTRL_ODIV0_WIDTH = (PLX_CTRL_ODIV0_FIELD.start - PLX_CTRL_ODIV0_FIELD.stop + 1) VALID_CLOCK_DIV_PRODUCTS = sorted(list(set( (np.multiply( np.arange(1 << PLX_CTRL_ODIV1_WIDTH).reshape( 1 << PLX_CTRL_ODIV1_WIDTH, 1), np.arange(1 << PLX_CTRL_ODIV0_WIDTH))).reshape(-1)))) if CPU_ARCH_IS_SUPPORTED: IOPLL_CTRL = Register(CRL_APB_ADDRESS + IOPLL_CTRL_OFFSET) RPLL_CTRL = Register(CRL_APB_ADDRESS + RPLL_CTRL_OFFSET) PL_CLK_CTRLS = [Register(CRL_APB_ADDRESS + PL0_CTRL_OFFSET), Register(CRL_APB_ADDRESS + PL1_CTRL_OFFSET), Register(CRL_APB_ADDRESS + PL2_CTRL_OFFSET), Register(CRL_APB_ADDRESS + PL3_CTRL_OFFSET)] ACPU_CTRL = Register(CRF_APB_ADDRESS + ACPU_CTRL_OFFSET) APLL_CTRL = Register(CRF_APB_ADDRESS + APLL_CTRL_OFFSET) DPLL_CTRL = Register(CRF_APB_ADDRESS + DPLL_CTRL_OFFSET) VPLL_CTRL = Register(CRF_APB_ADDRESS + VPLL_CTRL_OFFSET) PL_SRC_PLL_CTRLS = [IOPLL_CTRL, IOPLL_CTRL, RPLL_CTRL, DPLL_CTRL] ACPU_SRC_PLL_CTRLS = [APLL_CTRL, APLL_CTRL, DPLL_CTRL, VPLL_CTRL] else: warnings.warn("Pynq does not support the CPU Architecture: {}" .format(CPU_ARCH), ResourceWarning) @classmethod def set_pl_clk(mcs, clk_idx, div0=None, div1=None, clk_mhz=DEFAULT_PL_CLK_MHZ): """This method sets a PL clock frequency. Users have to specify the index of the PL clock to be changed. The CPU, and other source clocks, by default, should not get changed. Users have two options: 1. specify the two frequency divider values directly (div0, div1), or 2. specify the clock rate, in which case the divider values will be calculated. Note ---- In case `div0` and `div1` are both specified, the parameter `clk_mhz` will be ignored. Parameters ---------- clk_idx : int The index of the PL clock to be changed, from 0 to 3. div0 : int The first frequency divider value. div1 : int The second frequency divider value. clk_mhz : float The clock rate in MHz. """ pl_clk_reg = mcs.PL_CLK_CTRLS[clk_idx] pl_clk_reg[mcs.PLX_CTRL_CLKACT_FIELD] = 1 pl_clk_reg[mcs.PLX_CTRL_SRC_FIELD] = mcs.PLX_CTRL_SRC_DEFAULT super().set_pl_clk(clk_idx, div0, div1, clk_mhz) @classmethod def get_pll_mhz(mcs, pll_reg): """The getter method for PLL output clocks. Parameters ---------- pll_reg : Register The control register for a PLL Returns ------- float The PLL output clock rate measured in MHz. """ if pll_reg[mcs.CRX_APB_SRC_FIELD] != mcs.CRX_APB_SRC_DEFAULT: raise ValueError("Invalid PLL Source") pll_fbdiv = pll_reg[mcs.CRX_APB_FBDIV_FIELD] if pll_reg[mcs.CRX_APB_ODIVBY2_FIELD] == 1: pll_odiv2 = 2 else: pll_odiv2 = 1 return mcs.DEFAULT_SRC_CLK_MHZ * pll_fbdiv / pll_odiv2 @classmethod def get_cpu_mhz(mcs): """The getter method for CPU clock. The returned clock rate is measured in MHz. """ arm_src_pll_idx = mcs.ACPU_CTRL[mcs.ACPU_CTRL_SRC_FIELD] arm_clk_odiv = mcs.ACPU_CTRL[mcs.ACPU_CTRL_ODIV_FIELD] src_pll_reg = mcs.ACPU_SRC_PLL_CTRLS[arm_src_pll_idx] return round(mcs.get_pll_mhz(src_pll_reg) / arm_clk_odiv, 6) class _ClocksZynq(_ClocksMeta): """Implementation class for all Zynq 7-Series PS and PL clocks not exposed to users. Since this is the abstract base class for all Zynq 7-Series clocks, no attributes or methods are exposed to users. Users should use the class `Clocks` instead. """ DEFAULT_SRC_CLK_MHZ = 50.0 SLCR_BASE_ADDRESS = 0xF8000000 ARM_PLL_CTRL_OFFSET = 0x100 DDR_PLL_CTRL_OFFSET = 0x104 IO_PLL_CTRL_OFFSET = 0x108 SRC_PLL_FBDIV_FIELD = slice(18, 12) FCLK0_CTRL_OFFSET = 0x170 FCLK1_CTRL_OFFSET = 0x180 FCLK2_CTRL_OFFSET = 0x190 FCLK3_CTRL_OFFSET = 0x1A0 FCLKX_CTRL_ODIV1_FIELD = slice(25, 20) FCLKX_CTRL_ODIV0_FIELD = slice(13, 8) FCLKX_CTRL_SRC_FIELD = slice(5, 4) PL_CLK_SRC_FIELD = FCLKX_CTRL_SRC_FIELD PL_CLK_ODIV0_FIELD = FCLKX_CTRL_ODIV0_FIELD PL_CLK_ODIV1_FIELD = FCLKX_CTRL_ODIV1_FIELD ARM_CLK_CTRL_OFFSET = 0x120 ARM_CLK_ODIV_FIELD = slice(13, 8) ARM_CLK_SRC_FIELD = slice(5, 4) FCLKX_CTRL_ODIV1_WIDTH = (FCLKX_CTRL_ODIV1_FIELD.start - FCLKX_CTRL_ODIV1_FIELD.stop + 1) FCLKX_CTRL_ODIV0_WIDTH = (FCLKX_CTRL_ODIV0_FIELD.start - FCLKX_CTRL_ODIV0_FIELD.stop + 1) VALID_CLOCK_DIV_PRODUCTS = sorted(list(set( (np.multiply( np.arange(1 << FCLKX_CTRL_ODIV1_WIDTH).reshape( 1 << FCLKX_CTRL_ODIV1_WIDTH, 1), np.arange(1 << FCLKX_CTRL_ODIV0_WIDTH))).reshape(-1)))) if CPU_ARCH_IS_SUPPORTED: ARM_PLL_CTRL = Register(SLCR_BASE_ADDRESS + ARM_PLL_CTRL_OFFSET) DDR_PLL_CTRL = Register(SLCR_BASE_ADDRESS + DDR_PLL_CTRL_OFFSET) IO_PLL_CTRL = Register(SLCR_BASE_ADDRESS + IO_PLL_CTRL_OFFSET) PL_SRC_PLL_CTRLS = [IO_PLL_CTRL, IO_PLL_CTRL, ARM_PLL_CTRL, DDR_PLL_CTRL] PL_CLK_CTRLS = [Register(SLCR_BASE_ADDRESS + FCLK0_CTRL_OFFSET), Register(SLCR_BASE_ADDRESS + FCLK1_CTRL_OFFSET), Register(SLCR_BASE_ADDRESS + FCLK2_CTRL_OFFSET), Register(SLCR_BASE_ADDRESS + FCLK3_CTRL_OFFSET)] ARM_CLK_CTRL = Register(SLCR_BASE_ADDRESS + ARM_CLK_CTRL_OFFSET) ARM_SRC_PLL_CTRLS = [ARM_PLL_CTRL, ARM_PLL_CTRL, DDR_PLL_CTRL, IO_PLL_CTRL] else: warnings.warn("Pynq does not support the CPU Architecture: {}" .format(CPU_ARCH), ResourceWarning) @classmethod def set_pl_clk(mcs, clk_idx, div0=None, div1=None, clk_mhz=DEFAULT_PL_CLK_MHZ): """This method sets a PL clock frequency. Users have to specify the index of the PL clock to be changed. The CPU, and other source clocks, by default, should not get changed. Users have two options: 1. specify the two frequency divider values directly (div0, div1), or 2. specify the clock rate, in which case the divider values will be calculated. Note ---- In case `div0` and `div1` are both specified, the parameter `clk_mhz` will be ignored. Parameters ---------- clk_idx : int The index of the PL clock to be changed, from 0 to 3. div0 : int The first frequency divider value. div1 : int The second frequency divider value. clk_mhz : float The clock rate in MHz. """ super().set_pl_clk(clk_idx, div0, div1, clk_mhz) @classmethod def get_pll_mhz(mcs, pll_reg): """The getter method for PLL output clocks. Parameters ---------- pll_reg : Register The control register for a PLL Returns ------- float The PLL output clock rate measured in MHz. """ pll_fbdiv = pll_reg[mcs.SRC_PLL_FBDIV_FIELD] clk_mhz = mcs.DEFAULT_SRC_CLK_MHZ * pll_fbdiv return round(clk_mhz, 6) @classmethod def get_cpu_mhz(mcs): """The getter method for the CPU clock. Returns ------- float The CPU clock rate measured in MHz. """ arm_src_pll_idx = mcs.ARM_CLK_CTRL[mcs.ARM_CLK_SRC_FIELD] arm_clk_odiv = mcs.ARM_CLK_CTRL[mcs.ARM_CLK_ODIV_FIELD] src_pll_reg = mcs.ARM_SRC_PLL_CTRLS[arm_src_pll_idx] return round(mcs.get_pll_mhz(src_pll_reg) / arm_clk_odiv, 6) if CPU_ARCH == ZU_ARCH: _ClockParent = _ClocksUltrascale elif CPU_ARCH == ZYNQ_ARCH: _ClockParent = _ClocksZynq else: _ClockParent = object warnings.warn("PYNQ does not support the CPU Architecture: " "{}".format(CPU_ARCH))
[docs]class Clocks(_ClockParent, metaclass=_ClocksMeta): """Class for all the PS and PL clocks exposed to users. With this class, users can get the CPU clock and all the PL clocks. Users can also set PL clocks to other values using this class. Attributes ---------- cpu_mhz : float The clock rate of the CPU, measured in MHz. fclk0_mhz : float The clock rate of the PL clock 0, measured in MHz. fclk1_mhz : float The clock rate of the PL clock 1, measured in MHz. fclk2_mhz : float The clock rate of the PL clock 2, measured in MHz. fclk3_mhz : float The clock rate of the PL clock 3, measured in MHz. """ pass