Compaq EV68A specifications 40Internal Processor Registers

Cbox CSRs and IPRs

;INIT_MODE = 0

;BC_SIZE = 0xF

;INVALID_TO_DIRTY_ENABLE = 3

;ENABLE_EVICT = 1

;SET_DIRTY_ENABLE = 6

;BC_BANK_ENABLE = 1

;BC_WRT_STS = 0

;

;The value for the write_many chain is based on Table 5–25.

;The value is sampled from MSB, 6 bits at a time, as it is written

;to EV6__DATA. Therefore, before the value can be shifted in, it must be

;inverted on a by 6 basis. The code then writes out 6 bits at a time,

;shifting right by 6 after each write.

;

;So the following transformation is done on the write_many value:

;[35:30][29:24][23:18][17:12][11:06][05:00] =>

;[05:00][11:06][17:12][23:18][29:24][35:30]

;

;WRITE_MANY chain = 0x07FBFFFFD

;value to be shifted in = 0xF7FFEFFC1

;Before the chain can be written, I_CTL[SBE] must be disabled,

;and the code must be forced into the Icache.

;

ALIGN_CACHE_BLOCK <^x47FF041F>; align with nops

mb
lda	r0, ^x0086(r31)
hw_mtpr	r0, EV6__I_CTL
br	r0, .
addq	r0, #17, r0
hw_mtpr r31, EV6__IC_FLUSH
bne	r31, .
hw_jmp_stall (r0)
ALIGN_CACHE_BLOCK <^x47FF041F>
bc_config:
mb
lda	r1, ^xFFC1(r31)
ldah	r0, ^x7FFE(r31)
zap	r1, #^x0c, r1
bis	r1, r0, r1
addq	r31, #6, r0
bc_config_shift_in:
hw_mtpr	r1, EV6__DATA
subq	r0, #1, r0
beq	r0, bc_config_done
srl	r1, #6, r1
br	r31, bc_config_shift_in
bc_config_done:
hw_mtpr	r31, <EV6__MM_STAT ! 64>
beq	r31, bc_config_end
br	r31, .-4
bis	r31, r31, r31
bis	r31, r31, r31

;wait for MEM-OP’s to complete

;load I_CTL.....

;.....SDE=2, IC_EN=3, SBE=0

;create dest address

;finish computing dest address

;flush the Icache

;separate retires

;force flush

;align with nops

;pull this block in Icache

;data[15:00] = 0xFFC1

;data[31:16] = 0x7FFE

;clear out bits [31:16]

;or in bits [31:16]

;shift in 6 x 6 bits

;shift in 6 bits

;decrement R0

;done if R0 is zero

;align next 6 bits

;continue shifting

;wait until last shift

;predicts fall thru

;predict infinite loop

;nop

;nop

bc_config_end:

5–40Internal Processor Registers 21264/EV68A Hardware Reference Manual