Control And Peripheral Registers; Control Registers; Peripheral Registers - ZiLOG Z8 PLUS User Manual

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CONTROL AND PERIPHERAL REGISTERS

Control Registers

The standard control registers govern the operation of the CPU. Any instruction which references the register
file can access these control registers. Available control registers are:
Stack Pointer Low (SPL or STKPTR)
Stack Pointer High (SPH)
Register Pointer (RP or REGPTR)
Flags (FLAGS)
Interrupt Mask 1 (IMASK)
Interrupt Request 1 (IREQ)
Interrupt Mask 2 (IMASK2)
Interrupt Request 2 (IREQ2)
A 16-bit Program Counter (PC) to determine the sequence of current program instructions. The PC is not an
addressable register.

Peripheral Registers

Peripheral registers are used to transfer data, configure the operating mode, and control the operation of the
on-chip peripherals. Any instruction that references the register file can access the peripheral registers.
Possible peripheral registers can include:
Timer Count Value Register for Timer n
Auto-Initialization Value Register(s) for Timer n
Timer Control Registers (High and Low Byte)
Watch-Dog Timer Registers (High and Low Byte)
In addition, the port registers are considered to be peripheral registers. Ports generally have at least the
following four dedicated registers which are readable and writable by software:
Port Input Value Register
Port Output Value Register
Port Control Register
Port Special Function Register