Freescale Semiconductor DSP56374 User Manual page 184

Using The Serial EEPROM Boot Mode
do y1,_endofYGPIO
bsr ReadData
move a1,y:(r2)+
nop
nop
nop
_endofYGPIO
bsr ReadData
move a1,r0
jmp r0
GLOBAL TransmitData
TransmitData
do n1,_endofTransGPIO
asl a
bcc _Send0s
_Send1s
bset #PH2_SI,mHPORT:PDRH
bra _SendClock
_Send0s
bclr #PH2_SI,mHPORT:PDRH
_SendClock
bclr #PH3_CLK,mHPORT:PDRH
nop
nop
bset #PH3_CLK,mHPORT:PDRH
_endofTransGPIO
rts
GLOBAL ReadData
ReadData
bclr #PH3_CLK,mHPORT:PDRH
do #24,_WordRead
bset #PH3_CLK,mHPORT:PDRH
movep mHPORT:PDRH,x0
nop
bclr #PH3_CLK,mHPORT:PDRH
bset #PH1_SO,x0
rol a1
nop
nop
_WordRead
rts
SHIReset
;*** Reset SHI ***
movep #$0,X:HCSR
;*** Set clock Rate ***
; Set to /64 for max crystal value (i.e., 25MHz/(8*8) = 390625
; Enable wide spike filter
movep #$003040,X:HCKR
;*** Check HTX is empty i.e., HTDE=1 ***
brclr #15,X:HCSR,*
move #$008243,X:HCSR
rep #256
nop
rts
A-14
DSP56374 Users Guide, Rev. 1.2
Freescale Semiconductor