from migen.genlib.record import Record
from migen.flow.actor import Sink, Source
-class UARTRX(Module):
- def __init__(self, pads, tuning_word):
- self.source = Source([("d", 8)])
-
- ###
-
- uart_clk_rxen = Signal()
- phase_accumulator_rx = Signal(32)
-
- rx = Signal()
- self.specials += MultiReg(pads.rx, rx)
- rx_r = Signal()
- rx_reg = Signal(8)
- rx_bitcount = Signal(4)
- rx_busy = Signal()
- rx_done = self.source.stb
- rx_data = self.source.d
- self.sync += [
- rx_done.eq(0),
- rx_r.eq(rx),
- If(~rx_busy,
- If(~rx & rx_r, # look for start bit
- rx_busy.eq(1),
- rx_bitcount.eq(0),
- )
- ).Else(
- If(uart_clk_rxen,
- rx_bitcount.eq(rx_bitcount + 1),
- If(rx_bitcount == 0,
- If(rx, # verify start bit
- rx_busy.eq(0)
- )
- ).Elif(rx_bitcount == 9,
- rx_busy.eq(0),
- If(rx, # verify stop bit
- rx_data.eq(rx_reg),
- rx_done.eq(1)
- )
- ).Else(
- rx_reg.eq(Cat(rx_reg[1:], rx))
- )
- )
- )
- ]
- self.sync += \
- If(rx_busy,
- Cat(phase_accumulator_rx, uart_clk_rxen).eq(phase_accumulator_rx + tuning_word)
- ).Else(
- Cat(phase_accumulator_rx, uart_clk_rxen).eq(2**31)
- )
-
-class UARTTX(Module):
- def __init__(self, pads, tuning_word):
- self.sink = Sink([("d", 8)])
-
- ###
-
- uart_clk_txen = Signal()
- phase_accumulator_tx = Signal(32)
-
- pads.tx.reset = 1
-
- tx_reg = Signal(8)
- tx_bitcount = Signal(4)
- tx_busy = Signal()
- self.sync += [
- self.sink.ack.eq(0),
- If(self.sink.stb & ~tx_busy & ~self.sink.ack,
- tx_reg.eq(self.sink.d),
- tx_bitcount.eq(0),
- tx_busy.eq(1),
- pads.tx.eq(0)
- ).Elif(uart_clk_txen & tx_busy,
- tx_bitcount.eq(tx_bitcount + 1),
- If(tx_bitcount == 8,
- pads.tx.eq(1)
- ).Elif(tx_bitcount == 9,
- pads.tx.eq(1),
- tx_busy.eq(0),
- self.sink.ack.eq(1),
- ).Else(
- pads.tx.eq(tx_reg[0]),
- tx_reg.eq(Cat(tx_reg[1:], 0))
- )
- )
- ]
- self.sync += [
- If(tx_busy,
- Cat(phase_accumulator_tx, uart_clk_txen).eq(phase_accumulator_tx + tuning_word)
- ).Else(
- Cat(phase_accumulator_tx, uart_clk_txen).eq(0)
- )
- ]
+from misoclib.com.uart import UARTRX, UARTTX
class UART(Module, AutoCSR):
def __init__(self, pads, clk_freq, baud=115200):