Figure 4-3 Dma Wait Example - Nintendo Ultra64 Programmer's Manual

Revision 1.0
DMA Wait Example
Figure 4-3
############################################
# Procedure to do DMA waits.
#
# Registers:
#
# $11
#
.name tmp,
DMAwait:
# request DMA access: (get semaphore)
WaitSpin:
.unname tmp
#
#
#############################################
used as tmp
$11
mfc0 tmp, SP_RESERVED
bne tmp, zero, DMAwait
# note delay slot
mfc0 tmp, DMA_BUSY
bne tmp, zero, WaitSpin
nop
jr return
# clear semaphore, delay slot
mtc0 zero, SP_RESERVED
DMA
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