HD6433308 Datasheet, PDF (251/349 Pages) Hitachi Semiconductor – Hitachi Single-Chip MicroComputer

Section 13. ROM
13.1 Overview
The H8/330 includes 16K bytes of high-speed, on-chip ROM. The on-chip ROM is connected to
the CPU via a 16-bit data bus. Both byte data and word data are accessed in two states, enabling
rapid data transfer and instruction fetching.
The H8/330 is available in two versions: one with electrically programmable ROM (PROM); the
other with masked ROM. The PROM version has a PROM mode in which the chip can be
programmed with a standard PROM writer.
The on-chip ROM is enabled or disabled depending on the MCU operating mode, which is
determined by the inputs at the mode pins (MD1 and MD0) when the chip comes out of the reset
state. See table 13-1.
Table 13-1. On-Chip ROM Usage in Each MCU Mode
Mode
Mode 1 (expanded mode)
Mode 2 (expanded mode)
Mode 3 (single-chip mode)
Mode pins
MD1
MD0
0
1
1
0
1
1
On-chip ROM
Disabled (external addresses)
Enabled
Enabled
241