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GDB and Hitachi microprocessors

GDB needs to know the following things to talk to your Hitachi SH, H8/300, or H8/500.

That you want to use ‘target hms’, the remote debugging interface for Hitachi microprocessors, or ‘target e7000’, the in-circuit emulator for the Hitachi SH and the Hitachi 300H. (‘target hms’ is the default when GDB is configured specifically for the Hitachi SH, H8/300, or H8/500.)

What serial device connects your host to your Hitachi board (the first serial device available on your host is the default).

What speed to use over the serial device.

Connecting to Hitachi boards

Use the special gdb command ‘device port’ if you need to explicitly set the serial device. The default, port, is the first available port on your host. This is only necessary on Unix hosts, where it is typically something like /dev/ttya.

gdb has another special command to set the communications speed: ‘speed bps’. This command also is only used from Unix hosts; on DOS hosts, set the line speed as usual from outside GDB with the DOS mode command (for instance, ‘mode com2:9600,n,8,1,p’ for a 9600 bps connection).

The ‘device’ and ‘speed’ commands are available only when you use a Unix host to debug your Hitachi microprocessor programs. If you use a DOS host, GDB depends on an auxiliary terminate-and-stay-resident program called asynctsr to communicate with the development board through a PC serial port. You must also use the DOS mode command to set up the serial port on the DOS side.

Using the E 7000 in-circuit emulator

You can use the E7000 in-circuit emulator to develop code for either the Hitachi SH or the H8/300H. Use one of these forms of the ‘target e7000’ command to connect GDB to your E7000:

target e7000 port speed
Use this form if your E7000 is connected to a serial port. The port argument identifies what serial port to use (for example, ‘com2’). The third argument is the line speed in bits per second (for example, ‘9600’).

target e7000 hostname
If your E7000 is installed as a host on a TCP/IP network, you can just specify its hostname; GDB uses telnet to connect.

Special GDB commands for Hitachi micros

Some GDB commands are available only on the H8/300 or the H8/500 configurations:

set machine h8300

set machine h8300h
Condition GDB for one of the two variants of the H8/300 architecture with ‘set machine’. You can use ‘show machine’ to check which variant is currently in effect.

set memory mod

show memory
Specify which H8/500 memory model (mod) you are using with ‘set memory’; check which memory model is in effect with ‘show memory’. The accepted values for mod are small, big, medium, and compact.