# Copyright (c) 2016, Xilinx, Inc.
# SPDX-License-Identifier: BSD-3-Clause
from . import Pmod_DevMode
from . import PMOD_SWCFG_DIOALL
from . import PMOD_DIO_BASEADDR
from . import PMOD_DIO_TRI_OFFSET
from . import PMOD_DIO_DATA_OFFSET
from . import PMOD_CFG_DIO_ALLINPUT
from . import PMOD_CFG_DIO_ALLOUTPUT
from . import PMOD_NUM_DIGITAL_PINS
[docs]class Pmod_IO(Pmod_DevMode):
"""This class controls the Pmod IO pins as inputs or outputs.
Note
----
The parameter 'direction' determines whether the instance is input/output:
'in' : receiving input from offchip to onchip.
'out' : sending output from onchip to offchip.
The index of the Pmod pins:
upper row, from left to right: {vdd,gnd,3,2,1,0}.
lower row, from left to right: {vdd,gnd,7,6,5,4}.
Attributes
----------
microblaze : Pmod
Microblaze processor instance used by this module.
index : int
The index of the Pmod pin, starting from 0.
direction : str
Input 'in' or output 'out'.
"""
def __init__(self, mb_info, index, direction):
"""Return a new instance of a Pmod IO object.
Parameters
----------
mb_info : dict
A dictionary storing Microblaze information, such as the
IP name and the reset name.
index: int
The index of the Pmod pin, starting from 0.
direction : str
Input 'in' or output 'out'.
"""
if index not in range(PMOD_NUM_DIGITAL_PINS):
raise ValueError("Valid pin indexes are 0 - {}."
.format(PMOD_NUM_DIGITAL_PINS-1))
if direction not in ['in', 'out']:
raise ValueError("Direction can only be 'in', or 'out'.")
super().__init__(mb_info, PMOD_SWCFG_DIOALL)
self.index = index
self.direction = direction
self.start()
if self.direction == 'in':
self.write_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_TRI_OFFSET,
PMOD_CFG_DIO_ALLINPUT)
else:
self.write_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_TRI_OFFSET,
PMOD_CFG_DIO_ALLOUTPUT)
[docs] def write(self, value):
"""Send the value to the offboard Pmod IO device.
Note
----
Only use this function when direction is 'out'.
Parameters
----------
value : int
The value to be written to the Pmod IO device.
Returns
-------
None
"""
if value not in (0, 1):
raise ValueError("Pmod IO can only write 0 or 1.")
if not self.direction == 'out':
raise ValueError('Pmod IO used as output, declared as input.')
if value:
cur_val = self.read_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_DATA_OFFSET)
new_val = cur_val | (0x1 << self.index)
self.write_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_DATA_OFFSET, new_val)
else:
cur_val = self.read_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_DATA_OFFSET)
new_val = cur_val & (0xff ^ (0x1 << self.index))
self.write_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_DATA_OFFSET, new_val)
[docs] def read(self):
"""Receive the value from the offboard Pmod IO device.
Note
----
Only use this function when direction is 'in'.
Returns
-------
int
The data (0 or 1) on the specified Pmod IO pin.
"""
if not self.direction == 'in':
raise ValueError('Pmod IO used as input, but declared as output.')
raw_value = self.read_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_DATA_OFFSET)
return (raw_value >> self.index) & 0x1
def _state(self):
"""Retrieve the current state of the Pmod IO.
This function is usually used for debug purpose. Users should still
rely on read() or write() to get/put a value.
Returns
-------
int
The data (0 or 1) on the specified Pmod IO pin.
"""
raw_value = self.read_cmd(PMOD_DIO_BASEADDR +
PMOD_DIO_DATA_OFFSET)
return (raw_value >> self.index) & 0x1