SH7014 Datasheet, PDF (58/754 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

2. CPU
Table 2.3 Delayed Branch Instructions
SH7014/16/17 CPU
BRA
TRGET
ADD
R1,R0
Description
Executes an ADD before
branching to TRGET
Example of Conventional CPU
ADD.W R1,R0
BRA
TRGET
Multiplication/Accumulation Operation: 16-bit × 16-bit → 32-bit multiplication operations are
executed in one to two cycles. 16-bit × 16-bit + 64-bit → 64-bit multiplication/accumulation
operations are executed in two to three cycles. 32-bit × 32-bit → 64-bit and 32-bit × 32-bit + 64bit
→ 64-bit multiplication/accumulation operations are executed in two to four cycles.
T Bit: The T bit in the status register changes according to the result of the comparison, and in
turn is the condition (true/false) that determines if the program will branch. The number of
instructions that change the T bit is kept to a minimum to improve the processing speed (table
2.4).
Table 2.4 T Bit
SH7014/16/17 CPU
CMP/GE
BT
BF
R1,R0
TRGET0
TRGET1
ADD
CMP/EQ
BT
#1,R0
#0,R0
TRGET
Description
Example of Conventional CPU
T bit is set when R0 ≥ R1. The
program branches to TRGET0
when R0 ≥ R1 and to TRGET1
when R0 < R1.
CMP.W R1,R0
BGE TRGET0
BLT TRGET1
T bit is not changed by ADD. T bit is SUB.W #1,R0
set when R0 = 0. The program
branches if R0 = 0.
BEQ TRGET
Immediate Data: Byte (8-bit) immediate data resides in instruction code. Word or longword
immediate data is not input via instruction codes but is stored in a memory table. An immediate
data transfer instruction (MOV) accesses the memory table using the PC relative addressing mode
with displacement (table 2.5).
Rev.5.00 Sep. 27, 2007 Page 24 of 716
REJ09B0398-0500