IS80LV52 Datasheet, PDF (7/48 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP LOW VOLTAGE 8-BIT MICROCONTROLLER

IS80LV52
IS80LV32
ISSI ^®
OPERATING DESCRIPTION
The detail description of the IS80LV52/32 included in this indirect addressing only. Figure 6 shows internal data
description are:
memory organization and SFR Memory Map.
•Memory Map and Registers
•Timer/Counters
•Serial Interface
•Interrupt System
•Other Information
MEMORY MAP AND REGISTERS
Memory
The IS80LV52/32 has separate address spaces for program
and data memory. The program and data memory can be
up to 64K bytes long. The lower 8K program memory can
reside on-chip. (IS80LV52 only) Figure 5 shows a map of
the IS80LV52/32 program and data memory.
The IS80LV52/32 has 256 bytes of on-chip RAM, plus
numbers of special function registers. The lower 128 bytes
can be accessed either by direct addressing or by indirect
addressing. The upper 128 bytes can be accessed by
The lower 128 bytes of RAM can be divided into three
segments as listed below and shown in Figure 7.
1. Register Banks 0-3: locations 00H through 1FH
(32 bytes). The device after reset defaults to register
bank 0. To use the other register banks, the user must
select them in software. Each register bank contains
eight 1-byte registers R0-R7. Reset initializes the
stack point to location 07H, and is incremented once
to start from 08H, which is the first register of the
second register bank.
2. Bit Addressable Area: 16 bytes have been assigned
for this segment 20H-2FH. Each one of the 128 bits of
this segment can be directly addressed (0-7FH).
Each of the 16 bytes in this segment can also be
addressed as a byte.
3. Scratch Pad Area: 30H-7FH are available to the
user as data RAM. However, if the data pointer has
been initialized to this area, enough bytes should be
left aside to prevent SP data destruction.
Program Memory
(Read Only)
FFFFH:
64K
Data Memory
(Read/Write)
FFFFH:
External
EA = 0
External
1FFFH:
8K
0000
EA = 1
Internal
(IS80C52
Only)
PSEN
Internal
FFH:
00
0000
RD WR
Figure 5. IS80LV52/32 Program and Data Memory Structure
Integrated Silicon Solution, Inc. — 1-800-379-4774
7
ADVANCE INFORMATION MC019-0A
10/01/98