NEC PD754144 - Manual (Page 75)

CHAPTER 4 INTERNAL CPU FUNCTION
75 User’s Manual U10676EJ3V0UM
Table 4-4. Carry Flag Manipulation Instruction
Instruction (Mnemonic) Operation and Processing of Carry Flag
Carry flag manipulation SET1 CY Sets CY to 1
instruction CLR1 CY Clears CY to 0
NOT1 CY Inverts content of CY
SKT CY Skips if content of CY is 1
Bit transfer instruction MOV1 mem*.bit, CY Transfers content of CY to specified bit
MOV1 CY, mem*.bit Transfers content of specified bit to CY
Bit Boolean instruction AND1 CY, mem*.bit Takes ANDs, ORs, or XORs content of specified bit
OR1 CY, mem*.bit with content of CY and sets result to CY
XOR1 CY, mem*.bit
Interrupt service In interrupt execution Saved to stack memory in parallel with other PSW
bits in 8-bit units
RETI Restored from stack memory with other PSW bits
Remark mem*.bit indicates the following three bit manipulation addressing modes.
• fmem.bit
• pmem.@L
• @H+mem.bit
Example To AND bit 3 at address 3FH with P33 and output result to P60
MOV H, #3H ; Sets higher 4 bits of address to H register
MOV1 CY, @H+0FH.3 ; CY ← bit 3 of 3FH
AND1 CY, PORT3.3 ; CY ← CY P33
MOV1 PORT6.0, CY ; P60
← CY
(2) Skip flags (SK2, SK1, and SK0)
The skip flags record the skip status, and are automatically set or reset when the CPU executes an instruction.
These flags cannot be manipulated directly by the user as operands.
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