4.6.1.9 Emi Option

The -memi=mode option allows you to select the mode used by the external memory interface available on some PIC18 devices.

The interface can operate in a 16-bit word-write or byte-select mode; or in an 8-bit byte-write mode, and which are represented in the table below.

Table 4-11. External Memory Interface Modes
Mode Operation
wordwrite 16-bit word-write mode (default)
byteselect 16-bit byte-select mode
bytewrite 8-bit byte-write mode

For example, the option -memi=bytewrite will select the 8-bit byte-write mode.

The selected mode will affect the code generated when writing to the external data interface. In word write mode, dummy reads and writes can be added to ensure that an even number of bytes are always written. In byte-select or byte-write modes, dummy reads and writes are not generated and can result in more efficient code.

Note that this option does not pre-configure the device for the selected mode. Your device data sheet will indicate the settings required in your code.