Z08617 NMOS Z8
®
8-B
IT
MCU
K
EYBOARD
C
ONTROLLER
10
FUNCTIONAL DESCRIPTION
The device incorporates special functions to enhance
Zilog's Z8 applications as a keyboard controller, scien-
tific research and advanced technologies applications.
Program Memory.
The 16-bit program counter ad-
dresses 4 Kbytes of program memory space at inter-
nal locations (Figure 9).
The first 12 bytes of program memory are reserved for the
interrupt vectors. These locations have six 16-bit vectors
that correspond to the six available interrupts.
Byte 12 to byte 4095 consists of on-chip, mask
programmed ROM. Addresses 4096 and greater are
reserved.
12
11
10
9
8
7
6
5
4
3
2
1
0
On-Chip
ROM
Location of
First Byte of
Instruction
Executed
After RESET
Interrupt
Vector
(Lower Byte)
Interrupt
Vector
(Upper Byte)
IRQ5
IRQ4
IRQ4
IRQ3
IRQ3
IRQ2
IRQ2
IRQ1
IRQ1
IRQ0
IRQ0
IRQ5
65535
4096
4095
Reserved
Figure 9. Program Memory Map