
LTC1403-1/LTC1403A-1
17
14031fc
APPLICATIONS INFORMATION
; 10-23-03 ******************************************************************
; Files: 014SI.ASM -> 1403 bipolar Sine wave collection with Serial Port interface
;
bvectors.asm
buffered mode.
;
s2k14ini.asm
2k buffer size.
; first element at 1024, last element at 1023, two middles at 2047 and 0000
; bipolar mode
; Works 16 or 64 clock frames.
; negative edge BCLKR
; negative BFSR pulse
; -0 data shifted
; 1’ cable from counter to CONV at DUT
; 2’ cable from counter to CLK at DUT
; ***************************************************************************
.width
160
.length 110
.title “sineb0 BSP in auto buffer mode”
.mmregs
.setsect “.text”,
0x500,0
;Set address of executable
.setsect “vectors”, 0x180,0
;Set address of incoming 1403 data
.setsect “buffer”, 0x800,0
;Set address of BSP buffer for clearing
.setsect “result”, 0x1800,0
;Set address of result for clearing
.text
;.text marks start of code
start:
;this label seems necessary
;Make sure /PWRDWN is low at J1-9
;to turn off AC01 adc
tim=#0fh
prd=#0fh
tcr = #10h
; stop timer
tspc = #0h
; stop TDM serial port to AC01
pmst = #01a0h
; set up iptr. Processor Mode STatus register
sp = #0700h
; init stack pointer.
dp = #0
; data page
ar2 = #1800h
; pointer to computed receive buffer.
ar3 = #0800h
; pointer to Buffered Serial Port receive buffer
ar4 = #0h
; reset record counter
call sineinit
; Double clutch the initialization to insure a proper
sinepeek:
call sineinit
; reset. The external frame sync must occur 2.5 clocks
; or more after the port comes out of reset.
wait
goto
wait
;
————————Buffered Receive Interrupt Routine —————————
breceive:
ifr = #10h
; clear interrupt flags
TC = bitf(@BSPCE,#4000h) ; check which half (bspce(bit14)) of buffer
if (NTC) goto bufull
; if this still the first half get next half
bspce = #(2023h + 08000h); turn on halt for second half (bspce(bit15))
return _ enable
;
———————mask and shift input data ——————————————
bufull:
b = *ar3+ << -0
; load acc b with BSP buffer and shift right -0
b = #03FFFh & b
; mask out the TRISTATE bits with #03FFFh
b = b ^ #2000h
; invert the MSB for bipolar operation
B
*ar2+ = data(#0bh)
; store B to out buffer and advance AR2 pointer
TC = (@ar2 == #02000h) ; output buffer is 2k starting at 1800h
if (TC) goto start
; restart if out buffer is at 1fffh
goto bufull