HD64F2149 Datasheet, PDF (92/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

2.6.5 Notes on Use of Bit-Manipulation Instructions
The BSET, BCLR, BNOT, BST, and BIST instructions read a byte of data, carry out bit
manipulation, then write back the byte of data. Caution is therefore required when using these
instructions on a register containing write-only bits, or a port.
The BCLR instruction can be used to clear internal I/O register flags to 0. In this case, the relevant
flag need not be read beforehand if it is clear that it has been set to 1 in an interrupt handling
routine, etc.
2.7 Addressing Modes and Effective Address Calculation
2.7.1 Addressing Mode
The CPU supports the eight addressing modes listed in table 2.4. Each instruction uses a subset of
these addressing modes. Arithmetic and logic instructions can use the register direct and
immediate modes. Data transfer instructions can use all addressing modes except program-counter
relative and memory indirect. Bit-manipulation instructions use register direct, register indirect, or
absolute addressing mode to specify an operand, and register direct (BSET, BCLR, BNOT, and
BTST instructions) or immediate (3-bit) addressing mode to specify a bit number in the operand.
Table 2.4 Addressing Modes
No.
Addressing Mode
1
Register direct
2
Register indirect
3
Register indirect with displacement
4
Register indirect with post-increment
Register indirect with pre-decrement
5
Absolute address
6
Immediate
7
Program-counter relative
8
Memory indirect
Symbol
Rn
@ERn
@(d:16,ERn)/@(d:32,ERn)
@ERn+
@–ERn
@aa:8/@aa:16/@aa:24/@aa:32
#xx:8/#xx:16/#xx:32
@(d:8,PC)/@(d:16,PC)
@@aa:8
Register Direct—Rn: The register field of the instruction code specifies an 8-, 16-, or 32-bit
general register containing the operand. R0H to R7H and R0L to R7L can be specified as 8-bit
registers. R0 to R7 and E0 to E7 can be specified as 16-bit registers. ER0 to ER7 can be specified
as 32-bit registers.
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