Commit 75cc3ef8 authored by Bernd Porr's avatar Bernd Porr Committed by Kyle McMartin

usbdux: usbduxsigma: fixed timing issues between ADC and DAC

When sync ADC and the DAC was running at the same time the ADC
showed spikes in the signal. This happened when just before the
DRDY from the ADC was triggered a DAC interrupt was dealt with.
ADC and DAC share the same SPI bus and priority is now given the
ADC. The DAC values are now first stored in a buffer and
are only send to the DAC once the ADC has finished
converting all channels (start = 0) so that the SPI bus is
definitely quiet for about 100us.
Signed-off-by: default avatarBernd Porr <mail@berndporr.me.uk>
Signed-off-by: default avatarKyle McMartin <kyle@kernel.org>
parent 09852eab
......@@ -30,17 +30,20 @@
.inc fx2-include.asm
;;; a couple of flags
;;; a couple of flags in high memory
.equ CMD_FLAG,80h ; flag for the next in transfer
.equ PWMFLAG,81h ; PWM on or off?
.equ MAXSMPL,82H ; maximum number of samples, n channellist
.equ MUXSG0,83H ; content of the MUXSG0 register
.equ SMPLCTR,84h
.equ DPTRL,85H
.equ DPTRH,86h
.equ ASYNC_ON,87h
.equ INTERVAL,88h ; uframe/frame interval
.equ INTCTR,89h ; interval counter
.equ DABUFFER,0F0h ; buffer with DA values
;;; in precious low memory but accessible within one clock cycle
.equ DPTRL,70H
.equ DPTRH,71h
.equ ASYNC_ON,72h
.equ SMPLCTR,73h
;;; actual code
.org 0000h ; after reset the processor starts here
......@@ -229,31 +232,24 @@ isr0:
push 06h ; R6
push 07h ; R7
mov r0,#ASYNC_ON
mov a,@r0
mov a,ASYNC_ON
jz noepsubmit
mov DPS,#0
mov r0,#DPTRL
mov dpl,@r0
inc r0
mov dph,@r0
mov dpl,DPTRL
mov dph,DPTRH
lcall readADCch ; read one channel
mov r0,#DPTRL
mov @r0,dpl
inc r0
mov @r0,dph
mov DPTRL,dpl
mov DPTRH,dph
mov r0,#SMPLCTR
mov a,@r0
mov a,SMPLCTR
dec a
mov @r0,a
mov SMPLCTR,a
jnz noepsubmit
mov r0,#ASYNC_ON
mov @r0,#0
mov ASYNC_ON,#0
clr IOA.7 ; START = 0
......@@ -303,9 +299,6 @@ main:
mov a,#00000011b ; allows skip
lcall syncdelaywr
mov IP,#0 ; all std 8051 int have low priority
mov EIP,#0FFH ; all FX2 interrupts have high priority
mov dptr,#INTSETUP ; IRQ setup register
mov a,#08h ; enable autovector
lcall syncdelaywr
......@@ -314,6 +307,9 @@ main:
mov a,#0
lcall syncdelaywr
mov IP,#01H ; int0 has highest interrupt priority
mov EIP,#0 ; all USB interrupts have low priority
lcall initAD ; init the ports to the converters
lcall initeps ; init the isochronous data-transfer
......@@ -341,8 +337,10 @@ initAD:
mov r0,#MAXSMPL ; length of channellist
mov @r0,#0 ; we don't want to accumlate samples
mov r0,#ASYNC_ON ; async enable
mov @r0,#0 ; we don't want to accumlate samples
mov ASYNC_ON,#0 ; async enable
mov r0,#DABUFFER
mov @r0,#0
mov OEA,#11100000b ; PortA7,A6,A5 Outputs
mov IOA,#01100000b ; /CS = 1 and START = 0
......@@ -589,8 +587,6 @@ sof_isr:
push 06h ; R6
push 07h ; R7
clr IE.7 ; make sure that no other int's disturbe us
mov r0,#INTCTR ; interval counter
mov a,@r0 ; get the value
dec a ; decrement
......@@ -631,18 +627,14 @@ sof_adc:
mov a,#0 ; just zero
movx @dptr,a ; pad it up
inc dptr ; algin along a 32 bit word
mov r0,#DPTRL
mov @r0,dpl
inc r0
mov @r0,dph
mov DPTRL,dpl
mov DPTRH,dph
mov r0,#MAXSMPL
mov a,@r0
mov r0,#SMPLCTR
mov @r0,a
mov SMPLCTR,a
mov r0,#ASYNC_ON
mov @r0,#1 ; enable data collection
mov ASYNC_ON,#1
epfull:
;; do the D/A conversion
......@@ -658,7 +650,13 @@ epfull:
lcall syncdelaywr ; wait for the rec to sync
lcall syncdelaywr ; wait for the rec to sync
epempty:
epempty:
mov a,IOA ; conversion running?
jb ACC.7,sofend
lcall DAsend
sofend:
;; clear INT2
mov a,EXIF ; FIRST clear the USB (INT2) interrupt request
clr acc.4
......@@ -669,8 +667,6 @@ epempty:
movx @DPTR,a
nosof:
setb IE.7 ; re-enable global interrupts
pop 07h
pop 06h
pop 05h
......@@ -795,8 +791,6 @@ ep1out_isr:
push 06h ; R6
push 07h ; R7
clr IE.7 ; block other interrupts
mov dptr,#0E780h ; FIFO buffer of EP1OUT
movx a,@dptr ; get the first byte
mov r0,#CMD_FLAG ; pointer to the command byte
......@@ -831,8 +825,7 @@ pwm_off:
sjmp over_da
initsgADchannel:
mov r0,#ASYNC_ON
mov @r0,#0 ; make sure that no async activity is on
mov ASYNC_ON,#0
mov dptr,#0e781h ; FIFO buffer of EP1OUT
lcall configADC ; configures the ADC esp sel the channel
......@@ -869,13 +862,11 @@ startadc2:
inc dptr
mov r0,#MAXSMPL
mov @r0,a ; length of the channel list
mov r0,#SMPLCTR
mov @r0,a
mov SMPLCTR,a
lcall configADC ; configures all registers
mov r0,#ASYNC_ON ; async enable
mov @r0,#1 ; enable it
mov ASYNC_ON,#1 ; async enable
lcall reset_ep6 ; reset FIFO
......@@ -958,8 +949,6 @@ over_da:
mov a,#00001000b ; clear the ep1outirq
movx @DPTR,a
setb IE.7 ; re-enable interrupts
pop 07h
pop 06h
pop 05h
......@@ -979,19 +968,45 @@ over_da:
;;; all channels
;;; save all DA channels from the endpoint buffer in a local buffer
dalo:
movx a,@dptr ; number of bytes to send out
inc dptr ; pointer to the first byte
mov r1,#DABUFFER ; buffer for DA values
mov @r1,a ; save it
inc r1 ; inc pointer to local buffer
mov r0,a ; counter
nextDA:
nextDAlo:
movx a,@dptr ; get the byte
inc dptr ; point to the high byte
mov r3,a ; store in r3 for writeDA
mov @r1,a ; save it in the buffer
inc r1
movx a,@dptr ; get the channel number
inc dptr ; get ready for the next channel
mov @r1,a ; save it
inc r1
djnz r0,nextDAlo ; next channel
ret
;;; write to the DA converter
DAsend:
mov r1,#DABUFFER ; buffer of the DA values
mov a,@r1 ; get the channel count
jz DAret ; nothing to do
inc r1 ; pointer to the first byte
mov r0,a ; counter
nextDA:
mov a,@r1 ; get the byte
inc r1 ; point to the high byte
mov r3,a ; store in r3 for writeDA
mov a,@r1 ; get the channel number
inc r1 ; get ready for the next channel
push 1 ; is modified in the subroutine
lcall writeDA ; write value to the DAC
pop 1 ; get the pointer back
djnz r0,nextDA ; next channel
DAret:
ret
......@@ -1014,7 +1029,7 @@ writeDA3:
rr a ; shift to the upper to the lower
djnz r1,writeDA3
orl a,r2 ; merge with the channel info
clr IOA.6 ; /SYNC of the DA to 0
clr IOA.6 ; /SYNC (/CS) of the DA to 0
lcall sendSPI ; send it out to the SPI
mov a,r3 ; get data again
anl a,#00001111b ; get the lower nibble
......@@ -1024,7 +1039,7 @@ writeDA4:
djnz r1,writeDA4
anl a,#11110000b ; make sure that's empty
lcall sendSPI
setb IOA.6 ; /SYNC of the DA to 1
setb IOA.6 ; /SYNC (/CS) of the DA to 1
noDA: ret
......
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