4571 Datasheet, PDF (15/126 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4571 Group
PROGRAM MEMORY (ROM)
The program memory is a mask ROM. 1 word of ROM is
composed of 10 bits. ROM is separated every 128 words by the
unit of page (addresses 0 to 127). Table 1 shows the ROM size
and pages. Figure 16 shows the ROM map of M34571G6.
Table 8 ROM size and pages
Part number
ROM (PROM) size
(× 10 bits)
Pages
M34571G4
4096 words
32 (0 to 31)
M34571G6
6144 words
48 (0 to 47)
M34571GD
16384 words
128 (0 to 127)
Note 1.Data in pages 64 to 127 can be referred with the TABP p
instruction after the SBK instruction is executed.
Data in pages 0 to 63 can be referred with the TABP p
instruction after the RBK instruction is executed.
A part of page 1 (addresses 008016 to 00FF16) is reserved for
interrupt addresses (Figure 17). When an interrupt occurs, the
address (interrupt address) corresponding to each interrupt is set
in the program counter, and the instruction at the interrupt
address is executed. When using an interrupt service routine,
write the instruction generating the branch to that routine at an
interrupt address.
Page 2 (addresses 010016 to 017F16) is the special page for
subroutine calls. Subroutines written in this page can be called
from any page with the 1-word instruction (BM). Subroutines
extending from page 2 to another page can also be called with the
BM instruction when it starts on page 2.
ROM pattern (bits 9 to 0) of all addresses can be used as data
areas with the TABP p instruction.
98 7 6 5 4 3 2 1
000016
007F16
008016
00FF16
010016
017F16
018016
Interrupt address page
Subroutine special page
0
Page 0
Page 1
Page 2
Page 3
3FFF16
Fig 16. ROM map of M34571GD
Page 127
9876543210
008016
External 0 interrupt address
008216
External 1 interrupt address
008416
Timer 1 interrupt address
ROM Code Protect Address
When selecting the protect bit write by using a serial
programmer or selecting protect enabled for writing shipment by
Renesas Technology corp., reading or writing from/to QzROM is
disabled by a serial programmer.
As for the QzROM product in blank, the ROM code is protected
by selecting the protect bit write at ROM writing with a serial
programmer.
As for the QzROM product shipped after writing, whether the
ROM code protect is used or not can be selected as ROM option
setup (“MASK option” written in the mask file converter) when
ordering.
008616
008816
Timer 2 interrupt address
Timer 3 interrupt address
008A16
008C16
008E16 ^{Voltage drop detection circuit interrupt address}
00FF16
Fig 17. Page 1 (addresses 008016 to 00FF16) structure
Rev.1.02 May 25, 2007 Page 15 of 124
REJ03B0179-0102