Z86L88 Datasheet, PDF (26/66 Pages) Zilog, Inc. – INFRARED REMOTE CONTROLLERS

Z86L88/81/86/87/89/73
IR/Low-Voltage Microcontroller
FUNCTIONAL DESCRIPTION
The Z86LXX family of IR CCP incorporates special func-
tions to enhance the Z8's functionality in consumer and
battery operated applications.
Program Memory. The Z86LXX family addresses
16/24/32 Kbytes of internal program memory. The first
twelve bytes are reserved for interrupt vectors. These lo-
cations contain the five 16-bit vectors which correspond to
the five available interrupts. In all cases, at addresses 32K
and greater, external program memory fetches will be ex-
ecuted (provided proper A/D port mode register settings).
Refer to external memory timing specifications. In Rom-
less mode, program memory fetches begin at address
000Ch and data memory fetches begin at address 0000h.
RAM. The Z86LXX devices all have 256 bytes of RAM
which make up the Register file.
65535
External
Data
Memory
32,768
32768
Location of
First Byte of
Instruction
Executed
After RESET
12
11
10
9
8
7
Interrupt
Vector
(Lower Byte) ⁶
5
4
Interrupt
Vector
(Upper Byte) ³
2
1
0
External ROM
On-Chip
ROM
Reset Start Address
Reserved
Reserved
IRQ4
IRQ4
IRQ3
IRQ3
IRQ2
IRQ2
IRQ1
IRQ1
IRQ0
IRQ0
Not Addressable
0
Figure 20. External Memory Map
External Memory (/DM). The Z86LXX addresses up to 32
Kbytes of external memory beginning at address 32768
(Figure 20). External data memory is included with, or sep-
arated from, the external program memory space. /DM, an
optional I/O function that is programmed to appear on P34,
is used to distinguish between data and program memory
space. The state of the /DM signal is controlled by the type
of instruction being executed. An LDC opcode references
PROGRAM (/DM inactive) memory, and an LDE instruc-
tion references data (/DM active Low) memory.
Figure 19. Program Memory Map(32K ROM)
26
PRELIMINARY
DS96LV00800