NEC PD754144 - Manual (Page 280)

CHAPTER 11 INSTRUCTION SET
280 User’s Manual U10676EJ3V0UM
BR $addr1
Function: PC 11-0
← addr1
addr1 = (PC–15) to (PC–1), (PC+2) to (PC+16)
This is a relative branch instruction that has a branch range of (–15 to –1) and (+2 to +16) from the current address.
It is not affected by a page boundary or block boundary.
BRCB !caddr
Function: PC 11-0
← caddr 11-0
caddr = 0000H to 0FFFH
Branches to an address specified by the program counter (PC
11-0
) replaced with 12-bit immediate data caddr.
Caution
The BRCB !caddr instruction usually branches execution in a block where the instruction exists. If the first byte
of this instruction is at address 0FFEH, however, execution does not branch to block 0 but to block 1.
7 0
0FFFH
1000H
Block 1
Block 0
Program memory
0FFEH
a
If the BRCB !caddr instruction is at position a in the figure above, execution branches to block 1 (unmounted), not
block 0.
Do not use the BRC !caddr instruction at the address 0FFEH.
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