circuitpython/ports/rp2/modules/rp2.py

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# rp2 module: uses C code from _rp2, plus asm_pio decorator implemented in Python.
# MIT license; Copyright (c) 2020-2021 Damien P. George
from _rp2 import *
from micropython import const
_PROG_DATA = const(0)
_PROG_OFFSET_PIO0 = const(1)
_PROG_OFFSET_PIO1 = const(2)
_PROG_EXECCTRL = const(3)
_PROG_SHIFTCTRL = const(4)
_PROG_OUT_PINS = const(5)
_PROG_SET_PINS = const(6)
_PROG_SIDESET_PINS = const(7)
_PROG_MAX_FIELDS = const(8)
class PIOASMError(Exception):
pass
class PIOASMEmit:
def __init__(
self,
*,
out_init=None,
set_init=None,
sideset_init=None,
in_shiftdir=0,
out_shiftdir=0,
autopush=False,
autopull=False,
push_thresh=32,
pull_thresh=32
):
from array import array
self.labels = {}
execctrl = 0
shiftctrl = (
(pull_thresh & 0x1F) << 25
| (push_thresh & 0x1F) << 20
| out_shiftdir << 19
| in_shiftdir << 18
| autopull << 17
| autopush << 16
)
self.prog = [array("H"), -1, -1, execctrl, shiftctrl, out_init, set_init, sideset_init]
self.wrap_used = False
if sideset_init is None:
self.sideset_count = 0
elif isinstance(sideset_init, int):
self.sideset_count = 1
else:
self.sideset_count = len(sideset_init)
def start_pass(self, pass_):
if pass_ == 1:
if not self.wrap_used and self.num_instr:
self.wrap()
self.delay_max = 31
if self.sideset_count:
self.sideset_opt = self.num_sideset != self.num_instr
if self.sideset_opt:
self.prog[_PROG_EXECCTRL] |= 1 << 30
self.sideset_count += 1
self.delay_max >>= self.sideset_count
self.pass_ = pass_
self.num_instr = 0
self.num_sideset = 0
def __getitem__(self, key):
return self.delay(key)
def delay(self, delay):
if self.pass_ > 0:
if delay > self.delay_max:
raise PIOASMError("delay too large")
self.prog[_PROG_DATA][-1] |= delay << 8
return self
def side(self, value):
self.num_sideset += 1
if self.pass_ > 0:
set_bit = 13 - self.sideset_count
self.prog[_PROG_DATA][-1] |= self.sideset_opt << 12 | value << set_bit
return self
def wrap_target(self):
self.prog[_PROG_EXECCTRL] |= self.num_instr << 7
def wrap(self):
assert self.num_instr
self.prog[_PROG_EXECCTRL] |= (self.num_instr - 1) << 12
self.wrap_used = True
def label(self, label):
if self.pass_ == 0:
if label in self.labels:
raise PIOASMError("duplicate label {}".format(label))
self.labels[label] = self.num_instr
def word(self, instr, label=None):
self.num_instr += 1
if self.pass_ > 0:
if label is None:
label = 0
else:
if not label in self.labels:
raise PIOASMError("unknown label {}".format(label))
label = self.labels[label]
self.prog[_PROG_DATA].append(instr | label)
return self
def nop(self):
return self.word(0xA042)
def jmp(self, cond, label=None):
if label is None:
label = cond
cond = 0 # always
return self.word(0x0000 | cond << 5, label)
def wait(self, polarity, src, index):
if src == 6:
src = 1 # "pin"
elif src != 0:
src = 2 # "irq"
return self.word(0x2000 | polarity << 7 | src << 5 | index)
def in_(self, src, data):
if not 0 < data <= 32:
raise PIOASMError("invalid bit count {}".format(data))
return self.word(0x4000 | src << 5 | data & 0x1F)
def out(self, dest, data):
if dest == 8:
dest = 7 # exec
if not 0 < data <= 32:
raise PIOASMError("invalid bit count {}".format(data))
return self.word(0x6000 | dest << 5 | data & 0x1F)
def push(self, value=0, value2=0):
value |= value2
if not value & 1:
value |= 0x20 # block by default
return self.word(0x8000 | (value & 0x60))
def pull(self, value=0, value2=0):
value |= value2
if not value & 1:
value |= 0x20 # block by default
return self.word(0x8080 | (value & 0x60))
def mov(self, dest, src):
if dest == 8:
dest = 4 # exec
return self.word(0xA000 | dest << 5 | src)
def irq(self, mod, index=None):
if index is None:
index = mod
mod = 0 # no modifiers
return self.word(0xC000 | (mod & 0x60) | index)
def set(self, dest, data):
return self.word(0xE000 | dest << 5 | data)
_pio_funcs = {
# source constants for wait
"gpio": 0,
# "pin": see below, translated to 1
# "irq": see below function, translated to 2
# source/dest constants for in_, out, mov, set
"pins": 0,
"x": 1,
"y": 2,
"null": 3,
"pindirs": 4,
"pc": 5,
"status": 5,
"isr": 6,
"osr": 7,
"exec": 8, # translated to 4 for mov, 7 for out
# operation functions for mov's src
"invert": lambda x: x | 0x08,
"reverse": lambda x: x | 0x10,
# jmp condition constants
"not_x": 1,
"x_dec": 2,
"not_y": 3,
"y_dec": 4,
"x_not_y": 5,
"pin": 6,
"not_osre": 7,
# constants for push, pull
"noblock": 0x01,
"block": 0x21,
"iffull": 0x40,
"ifempty": 0x40,
# constants and modifiers for irq
# "noblock": see above
# "block": see above
"clear": 0x40,
"rel": lambda x: x | 0x10,
# functions
"wrap_target": None,
"wrap": None,
"label": None,
"word": None,
"nop": None,
"jmp": None,
"wait": None,
"in_": None,
"out": None,
"push": None,
"pull": None,
"mov": None,
"irq": None,
"set": None,
}
def asm_pio(**kw):
emit = PIOASMEmit(**kw)
def dec(f):
nonlocal emit
gl = _pio_funcs
gl["wrap_target"] = emit.wrap_target
gl["wrap"] = emit.wrap
gl["label"] = emit.label
gl["word"] = emit.word
gl["nop"] = emit.nop
gl["jmp"] = emit.jmp
gl["wait"] = emit.wait
gl["in_"] = emit.in_
gl["out"] = emit.out
gl["push"] = emit.push
gl["pull"] = emit.pull
gl["mov"] = emit.mov
gl["irq"] = emit.irq
gl["set"] = emit.set
old_gl = f.__globals__.copy()
f.__globals__.clear()
f.__globals__.update(gl)
emit.start_pass(0)
f()
emit.start_pass(1)
f()
f.__globals__.clear()
f.__globals__.update(old_gl)
return emit.prog
return dec
# sideset_count is inclusive of enable bit
def asm_pio_encode(instr, sideset_count):
emit = PIOASMEmit()
emit.delay_max = 31
emit.sideset_count = sideset_count
if emit.sideset_count:
emit.delay_max >>= emit.sideset_count
emit.pass_ = 1
emit.num_instr = 0
emit.num_sideset = 0
gl = _pio_funcs
gl["nop"] = emit.nop
# gl["jmp"] = emit.jmp currently not supported
gl["wait"] = emit.wait
gl["in_"] = emit.in_
gl["out"] = emit.out
gl["push"] = emit.push
gl["pull"] = emit.pull
gl["mov"] = emit.mov
gl["irq"] = emit.irq
gl["set"] = emit.set
exec(instr, gl)
if len(emit.prog[_PROG_DATA]) != 1:
raise PIOASMError("expecting exactly 1 instruction")
return emit.prog[_PROG_DATA][0]