4509 Datasheet, PDF (17/142 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4509 Group
PROGRAM MEMOY (ROM)
1 word of program memory is composed of 10 bits. ROM is sepa-
rated every 128 words by the unit of page (addresses 0 to 127).
Table 1 shows the ROM size and pages. Figure 10 shows the ROM
map of M34509G4.
Table 1 ROM size and pages
Part number
M34509G4
M34509G4H
ROM (PROM) size
(✕ 10 bits)
4096 words
4096 words
Pages
32 (0 to 31)
32 (0 to 31)
9
000016
007F16
008016
00FF16
010016
017F16
018016
87654321
Interrupt address page
Subroutine special page
0
Page 0
Page 1
Page 2
Page 3
A part of page 1 (addresses 008016 to 00FF16) is reserved for inter-
rupt addresses (Figure 11). When an interrupt occurs, the address
(interrupt address) corresponding to each interrupt is set in the pro-
gram counter, and the instruction at the interrupt address is
executed. When using an interrupt service routine, write the instruc-
tion generating the branch to that routine at an interrupt address.
Page 2 (addresses 010016 to 017F16) is the special page for subrou-
tine 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 7 to 0) of all addresses can be used as data areas
with the TABP p instruction.
ROM Code Protect Address
When selecting the protect bit write by using a serial programmer or
selecting protect enabled for writing shipment by Renesas Technol-
ogy 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 pro-
grammer.
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.
0FFF16
Page 31
Fig. 10 ROM map of M34509G4
98 7 6 5 4 3 2 10
008016 External 0 interrupt address
008216
008416
008616
Timer 1 interrupt address
Timer 2 interrupt address
008816
008A16
008C16
A/D interrupt address
008E16 Serial interface interrupt address
00FF16
Fig. 11 Page 1 (addresses 008016 to 00FF16) structure
Rev.1.02 2006.12.22 page 17 of 140
REJ03B0147-0102