Section 6 ROM
6.1
Overview
The H8/3882 and H8/3842 have 16 kbytes of mask ROM, the H8/3883 and H8/3843 have 24
kbytes of mask ROM, the H8/3884 and H8/3844 have 32 kbytes of mask ROM, the H8/3885 and
H8/3845 have 40 kbytes of mask ROM, the H8/3886 and H8/3846 have 48 kbytes of mask ROM,
and the H8/3887 and H8/3847 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 H8/3887 and H8/3847 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'7FFE
H'7FFE
H'7FFF
Even-numbered
address
Odd-numbered
address
Figure 6-1 ROM Block Diagram (H8/3884 and H8/3844)
118
ETC [ ETC ]
