HD64F2638F20J Datasheet, PDF (845/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 21B ROM
(H8S/2638 Group, H8S/2639 Group, H8S/2630 Group)
Section 21B ROM
(H8S/2638 Group, H8S/2639 Group, H8S/2630 Group)
21B.1 Overview
The H8S/2638 and H8S/2639 have 256 kbytes of on-chip flash memory, or 256 kbytes or 384
kbytes of on-chip mask ROM. The H8S/2630 has 384 kbytes of on-chip flash memory, or 384
kbytes of on-chip mask ROM. The ROM is connected to the bus master via a 16-bit data bus,
enabling both byte and word data to be accessed in one state. Instruction fetching is thus speeded
up, and processing speed increased.
The on-chip ROM is enabled and disabled by setting the mode pins (MD2 to MD0).
The flash memory version can be erased and programmed on-board, as well as with a special-
purpose PROM programmer.
21B.1.1 Block Diagram
Figure 21B-1 shows a block diagram of 256-kbyte and 384-kbyte ROM.
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'000000
H'000002
H'000001
H'000003
H'03FFFE
(H'05FFFE)*
H'03FFFF
(H'05FFFF)*
Note: * ROM addresses for the H8S/2638 and H8S/2639 extend from H'000000 to H'03FFFF (256 kbytes),
and for the H8S/2630 from H'000000 to H'05FFFF (384 kbytes).
Figure 21B-1 Block Diagram of ROM 256 kbytes (384 kbytes)^*
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 795 of 1458