HD6433937 Datasheet, PDF (131/521 Pages) Hitachi Semiconductor – Hardware Manual

Section 6 ROM
6.1 Overview
The H8/3935 and H8/3935R have 40 kbytes of mask ROM, the H8/3936 and H8/3936R have 48
kbytes of mask ROM, and the H8/3937 and H8/3937R have 60 kbytes of mask ROM on-chip.
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 H8/3937 and H8/3937R have a ZTAT™ version with 60-kbyte
PROM.
6.1.1 Block Diagram
Figure 6-1 shows a block diagram of the on-chip ROM.
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'0000
H'0002
H'0000
H'0002
H'0001
H'0003
On-chip ROM
H'9FFE
H'9FFE
Even-numbered
address
H'9FFF
Odd-numbered
address
Figure 6-1 ROM Block Diagram (H8/3935, H8/3935R)
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