Section 17 ROM
17.1 Overview
The H8/532 includes 32K bytes of high-speed, on-chip ROM. The on-chip ROM is connected to
the CPU via a 16-bit data bus and is accessed in two states.
Users wishing to program the chip themselves can request electrically programmable ROM
(PROM). The PROM version of the H8/532 has a PROM mode in which the chip can be
programmed with a standard, external PROM writer. The chip is also available with masked
ROM.
The on-chip ROM is enabled or disabled depending on the MCU operating mode, which is
determined by the inputs at the mode pins when the chip comes out of the reset state.
See table 17-1.
Table 17-1 ROM Usage in Each MCU Mode
Mode Pins
Mode MD
2 MD1 MD0 ROM
Mode 1 (expanded minimum mode) 0 0 1 Disabled (external addresses)
Mode 2 (expanded minimum mode) 0 1 0 Enabled
Mode 3 (expanded maximum mode) 0 1 1 Disabled (external addresses)
Mode 4 (expanded maximum mode) 1 0 0 Enabled
Mode 7 (single-chip mode) 1 1 1 Enabled
17.1.1 Block Diagram
Figure 17-1 shows the block diagram of the on-chip ROM.
295
Downloaded from Elcodis.com electronic components distributor
To Next Page
Loading...
Need help?
General
