Z86L972 Datasheet, PDF (18/91 Pages) Zilog, Inc. – Low-Voltage Microcontrollers

Z86L972/Z86L973/Z86L974
Low-Voltage Microcontrollers
11
64K program memory address space (FF00h–FFFFh). Data can be written to the
executable RAM by using the LDC instruction.
Memory locations between 8000h and FEFFh have not been implemented on this
microcontroller.
The Z86L972/Z86L973/Z86L974 family does not have the capability of accessing
external memory.
Location (Hex)
FFFF
FF00
3FFF (Z86L974)
1FFF (Z86L973)
FFF (Z86L972)
256 bytes
Executable RAM
Not Implemented
PROGRAM
MEMORY
000C
000B
000A
0009
0008
0007
0006
0005
0004
0003
0002
0001
0000
Figure 4.
Location of the first byte of the initial instruction executed after
RESET
IRQ₅ (lower byte)
IRQ₅ (upper byte)
IRQ₄ (lower byte)
IRQ₄ (upper byte)
IRQ₃ (lower byte)
IRQ₃ (upper byte)
IRQ₂ (lower byte)
IRQ₂ (upper byte)
IRQ₁ (lower byte)
IRQ₁ (upper byte)
IRQ₀ (lower byte)
IRQ₀ (upper byte)
Program Memory Map
Z8 Standard Register File (Bank 0)
Bank 0 of the Z8 expanded register file architecture is known as the standard reg-
ister file of the Z8. As shown in Figure 5, the Z8 standard register file consists of
16 groups of sixteen 8-bit registers known as Working Register (WR) groups.
Working Register Group F contains various control and status registers. The lower
half of Working Register Group 0 consists of I/O port registers (R0 to R7), the
upper eight registers are available for use as general-purpose RAM registers.
PS010504-1002
PRELIMINARY