Effect: This command specifies the size in bytes the read buffer must reach before the mega168’s status byte alerts the mega644 that the buffer is ready to be read. The value transmitted is a five-bit number representing
read-ready size - 1. That is to say, if the value transmitted to the mega168 is 0, read-ready size will be 1 and the read-ready status flag will be set after every received byte. If the value transmitted is 31, read-ready size will be 32 and the read-ready status flag will be set only when the read buffer is full. The default value for this setting is one (set the read-ready flag after every received byte).
This value can be saved to byte 16 of EEPROM using command 240 (Section 3.d.02) so that it will persist after a hardware reset. When storing in EEPROM, you must ensure the value is within the allowed range of 1 – 32.
Values sent: read-ready size – 1 (5 bits)
command byte = 227
data byte = read-ready size – 1