h8s-2635 Renesas Electronics Corporation., h8s-2635 Datasheet - Page 857

• Manufacturer Part Number: h8s-2635
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

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.
Note: * ROM addresses for the H8S/2638 and H8S/2639 extend from H'000000 to H'03FFFF (256 kbytes),
(H8S/2638 Group, H8S/2639 Group, H8S/2630 Group)
and for the H8S/2630 from H'000000 to H'05FFFF (384 kbytes).
Figure 21B-1 Block Diagram of ROM 256 kbytes (384 kbytes) *
Section 21B ROM (H8S/2638 Group, H8S/2639 Group, H8S/2630 Group)
(H'05FFFE)*
Section 21B ROM
H'03FFFE
H'000000
H'000002
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
(H'05FFFF)*
Rev. 6.00 Feb 22, 2005 page 797 of 1484
H'03FFFF
H'000001
H'000003
REJ09B0103-0600