Toshiba TX39 Computer Hardware User Manual


 
Architecture
112
BCzT Branch On Coprocessor z True BCzT
31 26 25 21 20 16 15 0
COPz
0100xx*
BC
01000
BCT
00001
offset
6 5 5 16
Format :
BCzT offset
Description :
Generates a branch target address by adding the address of the instruction in the delay slot to the 16-
bit offset (that has been left-shifted two bits and sign-extended to 32 bits). If the coprocessor z
condition (CPCOND) sampled during execution of the immediately preceding instruction is true, the
program branches to the target address after a one-cycle delay.
Operation :
T 1:
T:
T + 1:
condition COC[z]
target (offset
15
)
14
|| offset || 0
2
if condition then
PC PC + target
endif
*Refer also to the table on the following page (Operation Code Bit Encoding) or to the section
entitled Bit Encoding of CPU Instruction Opcodes at the end of this appendix.