Compaq 21264, EV67 specifications PALcode Restrictions and Guidelines D-7

Restriction 1 : Reset Sequence Required by Retire Logic and Mapper

mtpr	r31,EV6__PCTR_CTL	/* 2nd buffer fetch block for above map-stall
		/* and 2nd clear PCTR_CTL (SCRBRD=4)*/
bis	r31,1,r0	/* set up value for demon write*/
bis	r31,1,r0	/* set up value for demon write*/
mulq	r31,r31,r0	/* nop*/
lda	r0,0x780(r31)	/* this is new initialization stuff to
		prevent*/
mb
whint	r0	/* ld/st below from going off-chip */
mb
bis	r31,1,r0	/* set up value for demon write*/
ldq_p	r1,0x780(r31)	/* flush Pipe 0 LD logic*/
ldq_p	r0,0x788(r31)	/* flush Pipe 1 LD logic*/
mb		/* wait for LD’s to complete*/
mb		/* wait for LD’s to complete*/
stq_p	r1,0x780(r31)	/* flush Pipe 0 ST logic*/
stq_p	r0,0x788(r31)	/* flush Pipe 1 ST logic*/
bis	r31, 32, r0	/* load loop count of 32*/
jsr_init_loop:
bsr	r31,jsr_init_loop_nxt		/* JSR to PC+4*/
jsr_init_loop_nxt:
stq_p	r1,0x780(r31)	/* flush Pipe 0 ST logic*/
subq	r0,1,r0	/* decrement loop count*/
beq	r0,jsr_init_done	/* done?*/
br	r31,jsr_init_loop	/* continue loop*/
jsr_init_done:
lda	r0,0x03FF(r31)	/* create FP one..... */
sll	r0,52,r0	/* .....value = 0x3FF0000000000000 */
itoft	r0,f0	/* put it into F0 reg */
addq	r31,r31,r1	/* nop (also clears R1) */
mult	f0,f0,f0	/* flush mul-pipe */
addt	f0,f0,f0	/* flush add-pipe */
divt	f0,f0,f0	/* flush div-pipe */
sqrtt	f0,f0	/* flush div-pipe */
cvtqt	f0,f0	/* flush add-pipe (integer logic) */
perr r31,r31,r0		/* flush MVI logic */
maxuw4 r31,r31,r0		/* flush MVI logic */
pkwb	r31,r0	/* flush MVI logic */
rc	r0	/* clear interrupt flag*/
addq	r31,r31,r1	/* nop (also clears R1)*/
addq	r31,r31,r1	/* nop (also clears R1)*/
addq	r31,r31,r1	/* nop (also clears R1)*/
/*

*This palbase init exists for the rare cases

*when this code is loaded into upper memory.

*That is the case when this code is loaded

*and executed in memory on a system that has

*already been initialized. This technique

*can sometimes be used to debug snippets of

*this code.

*/

Alpha 21264/EV67 Hardware Reference Manual PALcode Restrictions and Guidelines D–7