Z89135 Datasheet, PDF (28/66 Pages) Zilog, Inc. – Low-Cost DTAD Controller

Z89135/136 (ROMless)
Low-Cost DTAD Controller
FUNCTIONAL DESCRIPTION
The Z8 CCP™ core incorporates special functions to en-
hance the Z8’s application in industrial, scientific research
and advanced technologies applications.
Reset. The device is reset in one of the following condi-
tions:
s Power-On Reset
s Watch-Dog Timer
s Stop-Mode Recovery Source
s External Reset
Program Memory. The Z8 addresses up to 24 KB of inter-
nal program memory and 40 KB external memory (Figure
16). The first 12 bytes of program memory are reserved for
the interrupt vectors. These locations contain six 16-bit
vectors that correspond to the five user interrupts and one
DSP interrupt. Byte 12 to byte 24575 consists of on-chip
mask-programmed ROM. At addresses 24576 and great-
er, the Z8 executes external program memory. In ROM-
less mode, the Z8 will execute external program memory
beginning at byte 12 and continuing through byte 65535.
Zilog
65535
24575
Location of
First Byte of
Instruction
Executed
After RESET ₁₂
11
10
9
8
7
Interrupt
Vector
(Lower Byte)
6
5
4
Interrupt
Vector ₃
(Upper Byte)
2
1
0
External
ROM and RAM
On-Chip
ROM
In ROM Mode
IRQ5
IRQ5
IRQ4
IRQ4
IRQ3
IRQ3
IRQ2
IRQ2
IRQ1
IRQ1
IRQ0
IRQ0
Figure 16. Program Memory Map
1-28
PRELIMINARY
DS97TAD0300