Z86E6116PSC Datasheet, PDF (22/69 Pages) Zilog, Inc. – Z86E61/Z86E63 CMOS Z8 16K/32K EPROM Microcontroller

Z86E61/E63
CMOS Z8 16K/32K EPROM Microcontroller
18
ADDRESS SPACE
Program Memory. The Z86E61/E63 can address 48 Kbytes (E61) or 32 Kbytes
(E63) of external program memory (Figure 11). The first 12 bytes of program
memory are reserved for the interrupt vectors. These locations contain six 16-bit
vectors that correspond to the six available interrupts. For EPROM mode, byte 13
to byte 16383 (E61) or 32767 (E63) consists of on-chip EPROM. At addresses
16384 (E61) or 32768 (E63) and above, the Z86E61/E63 executes external pro-
gram memory fetches. In ROMless mode, the Z86E61/E63 can address up to 64
Kbytes of program memory. Program execution begins at external location 000C
(HEX) after a reset.
65535
16384 (E61)
32768 (E63)
16383 (E61)
32767 (E63)
Location of ₁₂
First Byte of
Instruction 11
Executed
After RESET ¹⁰
9
8
Interrupt ⁷
Vector ₆
(Lower Byte)
5
Interrupt ⁴
Vector
(Upper Byte)
3
2
1
0
External
ROM and RAM
On-Chip PROM
IRQ5
IRQ5
IRQ4
IRQ4
IRQ3
IRQ3
IRQ2
IRQ2
IRQ1
IRQ1
IRQ0
IRQ0
Figure 11. Program Memory Configuration
Data Memory (DM)
The EPROM version can address up to 48 Kbytes (E61) or 32 Kbytes (E63) of
external data memory space beginning at location 16384 (E61) or 32768 (E63).
The ROMless version can address up to 64 Kbytes of external data memory.
External data memory may be included with, or separated from, the external pro-
gram memory space. DM, an optional I/0 function that can be programmed to
appear on pin P34, is used to distinguish between data and program memory
PS014401-1001