Operating Modes; On-Board Programming Modes; Table 24.3 Operating Modes And Rom; Table 24.4 On-Board Programming Mode Settings - Renesas H8S/2158 User Manual

24.6

Operating Modes

The flash memory is connected to the CPU via a 16-bit data bus, enabling byte data and word data
to be accessed in a single state. Even addresses are connected to the upper 8 bits and odd addresses
are connected to the lower 8 bits. Note that word data must start from an even address.
On-chip ROM is enabled or disabled by the mode select pins (MD2, MD1, and MD0) and the
EXPE bit in MDCR, as summarized in table 24.3.
In normal mode, up to 56 kbytes of ROM can be used.

Table 24.3 Operating Modes and ROM

Operating Modes
MCU CPU
Operating Operating
Mode Mode
Mode 2 Advanced
Advanced
Mode 3 Normal
Normal
24.7

On-Board Programming Modes

An on-board programming mode is used to perform on-chip flash memory programming, erasing,
and verification. This LSI has two on-board programming modes: boot mode and user program
mode. Table 24.4 shows pin settings for boot mode. In user program mode, operation by software
is enabled by setting control bits. For details on flash memory mode transitions, see figure 24.2.

Table 24.4 On-Board Programming Mode Settings

Mode Setting
Boot mode
User program mode
Mode
Single-chip mode
Extended mode with
on-chip ROM
Single-chip mode
Extended mode
without on-chip ROM
Mode 2 (advanced mode)
Mode 3 (normal mode)
Mode Pins
MD2 MD2
MD2 MD2
MD1 MD0
1 1 0
1 1 0
1 1 1
1 1 1
MD2 MD2 MD2 MD2
FWE
1 0
1 1
1 1
Rev. 3.00 Jan 25, 2006 page 727 of 872
Section 24 ROM
MDCR
On-Chip
EXPE ROM
0 Enabled
(256 kbytes)
1
0 Enabled
(56 kbytes)
1
MD1 MD0
0 0
1 0
1 1
REJ09B0286-0300