Datasheet

Section 22 ROM (H8S/2138 F-ZTAT A-Mask Version, H8S/2134 F-ZTAT A-Mask Version)
Rev. 4.00 Jun 06, 2006 page 623 of 1004
REJ09B0301-0400
Section 22 ROM
(H8S/2138 F-ZTAT A-Mask Version,
H8S/2134 F-ZTAT A-Mask Version)
22.1 Overview
H8S/2138 F-ZTAT A-mask version and H8S/2134 F-ZTAT A-mask version have 128 kbytes of
on-chip flash memory. The flash memory is connected to the bus master by a 16-bit data bus. The
bus master accesses both byte and word data in one state, enabling faster instruction fetches and
higher processing speed.
The mode pins (MD1 and MD0) and the EXPE bit in MDCR can be set to enable or disable the
on-chip ROM.
The flash memory version of this group can be erased and programmed on-board as well as with a
general-purpose PROM programmer.
22.1.1 Block Diagram
Figure 22.1 shows a block diagram of the ROM.
H'000000
H'000002
H'01FFFE
H'000001
H'000003
H'01FFFF
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
Figure 22.1 ROM Block Diagram