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suservo: move overflowing RTIO address bits into data

This commit is contained in:
Sebastien Bourdeauducq 2018-11-26 06:54:20 +08:00
parent ae8ef18f47
commit 450a035f9e
2 changed files with 26 additions and 13 deletions
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9
artiq/coredevice/suservo.py
View File

@ -129,7 +129,10 @@ class SUServo:
:param addr: Memory location address.
:param value: Data to be written.
"""
rtio_output((self.channel << 8) | addr | WE, value)
addr |= WE
value |= (addr >> 8) << COEFF_WIDTH
addr = addr & 0xff
rtio_output((self.channel << 8) | addr, value)
delay_mu(self.ref_period_mu)
@kernel
@ -140,7 +143,9 @@ class SUServo:
:param addr: Memory location address.
"""
rtio_output((self.channel << 8) | addr, 0)
value = (addr >> 8) << COEFF_WIDTH
addr = addr & 0xff
rtio_output((self.channel << 8) | addr, value)
return rtio_input_data(self.channel)
@kernel

30
artiq/gateware/rtio/phy/servo.py
View File

@ -43,11 +43,16 @@ class RTServoMem(Module):
# ensure that the DDS word data fits into the coefficient mem
assert w.coeff >= w.word
# coeff, profile, channel, 2 mems, rw
# this exceeds the 8-bit RTIO address, so we move the extra ("overflow")
# address bits into data.
internal_address_width = 3 + w.profile + w.channel + 1 + 1
rtlink_address_width = min(8, internal_address_width)
overflow_address_width = internal_address_width - rtlink_address_width
self.rtlink = rtlink.Interface(
rtlink.OInterface(
data_width=w.coeff,
# coeff, profile, channel, 2 mems, rw
address_width=3 + w.profile + w.channel + 1 + 1,
data_width=overflow_address_width + w.coeff,
address_width=rtlink_address_width,
enable_replace=False),
rtlink.IInterface(
data_width=w.coeff,
@ -65,30 +70,33 @@ class RTServoMem(Module):
[_.clip for _ in servo.iir.ctrl]))
]
assert len(self.rtlink.o.address) == (
assert len(self.rtlink.o.address) + len(self.rtlink.o.data) - w.coeff == (
1 + # we
1 + # state_sel
1 + # high_coeff
len(m_coeff.adr))
# ensure that we can fit config/status into the state address space
assert len(self.rtlink.o.address) >= (
assert len(self.rtlink.o.address) + len(self.rtlink.o.data) - w.coeff >= (
1 + # we
1 + # state_sel
1 + # config_sel
len(m_state.adr))
we = self.rtlink.o.address[-1]
state_sel = self.rtlink.o.address[-2]
config_sel = self.rtlink.o.address[-3]
high_coeff = self.rtlink.o.address[0]
internal_address = Signal(internal_address_width)
self.comb += internal_address.eq(Cat(self.rtlink.o.address, self.rtlink.o.data[w.coeff:]))
we = internal_address[-1]
state_sel = internal_address[-2]
config_sel = internal_address[-3]
high_coeff = internal_address[0]
self.comb += [
self.rtlink.o.busy.eq(0),
m_coeff.adr.eq(self.rtlink.o.address[1:]),
m_coeff.adr.eq(internal_address[1:]),
m_coeff.dat_w.eq(Cat(self.rtlink.o.data, self.rtlink.o.data)),
m_coeff.we[0].eq(self.rtlink.o.stb & ~high_coeff &
we & ~state_sel),
m_coeff.we[1].eq(self.rtlink.o.stb & high_coeff &
we & ~state_sel),
m_state.adr.eq(self.rtlink.o.address),
m_state.adr.eq(internal_address),
m_state.dat_w[w.state - w.coeff:].eq(self.rtlink.o.data),
m_state.we.eq(self.rtlink.o.stb & we & state_sel & ~config_sel),
]