6.1
Overview
The H8/38024, H8/38024S, and H8/38124 have 32 Kbytes of on-chip mask ROM, the H8/38023,
H8/38023S, and H8/38123 have 24 Kbytes, the H8/38022, H8/38022S, and H8/38122 have 16
Kbytes, the H8/38021, H8/38021S, and H8/38121 have 12 Kbytes, and the H8/38020, H8/38020S,
and H8/38120 have 8 Kbytes. The ROM is connected to the CPU by a 16-bit data bus, allowing
high-speed two-state access for both byte data and word data. The H8/38024 has a ZTAT version
and F-ZTAT version with 32-Kbyte PROM and flash memory. A F-ZTAT™ version of the
H8/38124 is available, and it has 32 Kbytes of flash memory.
Note: Mask ROM versions of the H8/38124, H8/38123, H8/38122, H8/38121, and H8/38120 are
under development.
6.1.1
Block Diagram
Figure 6.1 shows a block diagram of the on-chip ROM.
H'0000
H'0002
H'7FFE
Section 6 ROM
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'0000
H'0002
On-chip ROM
H'7FFE
Even-numbered
address
Figure 6.1 ROM Block Diagram (H8/38024)
H'0001
H'0003
H'7FFF
Odd-numbered
address
Rev. 6.00, 08/04, page 141 of 628