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How to write without reading to I/O register_HEW

Latest Updated:10/11/2017


When I try to write to the I/O register in the HEW memory window or I/O register window, read is also automatically performed. Is there any way to write to the register without reading it?


Open the command line window by going to the HEW menu bar and selecting [Display] -> [Command Line].
By using the command described below you can write to the I/O register without initiating a read.
(However, when using E8/E8a emulators, this is only effective for the H8 Family.)
Command: hdi memwrite
This command writes data to the target system memory.

hdi memwrite space address size data
Functions for the hdi memwrite command is as follows:
Space: specify the address of the space to be used. This is only for processors that have multiple address spaces. For single address space processors, specify "0".
Address: address of first data to be written.
Size: size of data to be written; 1 = byte, 2 = word, 4 = long word
Data: data to be written; A successful write will return an empty character string. An error will return an error character string.

hdi memwrite 0 ff00 1 ff
(when writing byte-data H'FF to address H'FF00)

If the target address is displayed in the memory window or I/O register window at this point, a read event has occurred.

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