Texas Instruments TMS320C2XX - Manual (Page 506)

Task-Specific Program Code
C-21 Program Examples
Example C–14. Using Synchronous Serial Port With Codec Device (ad55.asm)
* File: ad55.asm *
* Function: Burst mode simple loop back on AD55 CODEC *
* CODEC master clock 10 MHz *
* Simple I/O at 9.6-kHz sampling *
.title ”AD55 codec simple I/O” ; Title
.copy
”init.h” ; Variable and register declaration
.copy ”vector.h” ; Vector label declaration
.text
start: clrc cnf ; Map block B0 to data memory
ldp #0h ; set DP=0
setc intm ; Disable all interrupts
splk #0000h, 60h ; Set zero wait states
out 60h,wsgr
splk #0c002h,60h ; Initialize SSP
out 60h, sspcr ; reset the serial port by writing
splk #0c032h,60h ; zeros to reset bits,
out 60h,sspcr ; enable Sync port, 1 word fifo,
; CLX/FSR as inputs. Burst mode
main: splk #08h,imr ; enable RINT interrupt
splk #0ffffh, ifr ; reset ifr flags
mar *,ar1 ; load ar1 with rx buffer
lar ar1, #rxbuf
lar ar0, #size
* 0 0 R/W’ reg_add data ; AD55 command reg. bits
*D15 14 13 12 – 8 7–0
splk #0000h, 60h ; reg0 nop
splk #0304h, 61h ; reg1 8khz sampling
splk #0200h, 62h ; default data 00
splk #0301h, 63h ; default data 01
splk #0401h, 64h ; default data 01
splk #0508h, 65h ; default data 08
splk #0001h, 66h ; secondary comm. request data
out 66h,sdtr ; request sec. comm.
out 61h,sdtr ; send reg1 data for 9.6-Khz sampling
out 60h,sdtr ; send 0x0000 after programming
clrc intm ; Enable SSP interrupts
loop: clrc xf ; clear xf flag
idle ; Wait for SSP interrupt
b loop