Motorola DSP56012 User Manual page 232

Bootstrap ROM Contents
; "shild" is the routine that loads from the Serial Host Interface.
; MC:MB:MA = 101—bootstrap
; MC:MB:MA = 111—bootstrap
; If MC:MB:MA = 1X1, the internal Program RAM is loaded with 256 words
; received through the Serial Host Interface (SHI).
; The SHI operates in the Slave mode
; with the 10-word FIFO enabled, and with the HREQ pin enabled for
; receive operation. The word size for transfer is 24 bits. The SHI
; operates in the SPI or in the IIC mode, according to the bootstrap mode.
shild jclr
bset
shi_loop movep
do
jclr
movep
_loop2
; Exit bootstrap ROM
exit
clr a
andi
movep
jmp
; This code fills the unused bootstrap ROM locations with their address
dup $020-*
dc *
endm
A-6
from SHI (SPI)
from SHI (IIC)
#mb,omr,shi_loop ; If MC:MB:MA = 101, select SPI mode
#hi2c,r1
r1,x:hcsr
#256,_loop2
#hrne,x:hcsr,*
x:hrx,p:(r0)+
a0,r0
#$ec,omr
a1,x:bcr
(r0)
DSP56012 User's Manual
; otherwise select I2C mode.
; enable SHI
; wait for HRX not empty
; store in Program RAM
; r0 points to destination address
; set operating mode to 0
; (and trigger an exit from
; bootstrap mode).
; Delay needed for Op. Mode change
; used to clear BCR register.
; Then go to destination address.
MOTOROLA