GMS81004 Datasheet, PDF (27/101 Pages) Hynix Semiconductor – 8-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 2. Function Description
2.1.4.5 PUSH A(X, Y, PSW)
M(SP) ¡ç A
SP ¡ç SP - 1
2.1.4.6 POP A(X, Y, PSW)
SP ¡ç SP + 1
A ¡ç M(SP)
2.1.5 PC (Program Counter)
- Program counter is a 16-bit counter consisted of 8-bit register PCH and PCL.
- Addressing space is 64K bytes.
2.1.6 PSW (Program Status Word)
- PSW is an 8-bit register.
- Consisted of the flags showing the post state of operation and the flags determining
the CPU operation, initialized as 00H in reset state.
2.1.7 Flag register.
2.1.7.1 Carry flag (C)
- After operation, set when there is a carry from bit7 of ALU or there is not a borrow.
- Set by SETC and clear by CLRC.
- Executable as 1-bit accumulator.
- Branch condition flag of BCS, BCC.
2.1.7.2 Zero flag (Z)
- After operation also including 16-bit operatiion, set if the result is ¡È0¡È
- Branch condition flag of BEQ, BNE.
2.1.7.3 Interrupt enable flag (I)
- Master enable flag of interrupt except for RST (reset).
- Set and cleared by EI, DI
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