# Source code for pynq.lib.pmod.pmod_io

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from . import Pmod_DevMode
from . import PMOD_SWCFG_DIOALL
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

__author__ = "Yun Rock Qu"
__email__ = "pynq_support@xilinx.com"

[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':
PMOD_DIO_TRI_OFFSET,
PMOD_CFG_DIO_ALLINPUT)
else:
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:
PMOD_DIO_DATA_OFFSET)
new_val = cur_val | (0x1 << self.index)
PMOD_DIO_DATA_OFFSET, new_val)
else:
PMOD_DIO_DATA_OFFSET)
new_val = cur_val & (0xff ^ (0x1 << self.index))
PMOD_DIO_DATA_OFFSET, new_val)

"""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.')

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.

"""