AGB Programming Manual
Communication Functions
©1999 - 2001 Nintendo of America Inc.
128
D.C.N. AGB-06-0001-002B4
13.1 8-Bit/32-Bit Normal Serial Communication
Serial transfer sends/receives simultaneously.
If data is set in the data register and the serial transfer is started, received data is set
in the data register when the transfer is complete.
Connecting during normal serial communication
SI
SO
SD
SC
SI
SO
SD
SC
Master
Slave
Master (internal clock mode) will output the shift clock from SC terminal. SD terminal
will become an input terminal with pull-up.
In the case of a slave(external clock mode), SC terminal will become an input terminal
with pull-up. SD terminal will go to LO output.
The set data will be left-shifted by the falling of the shift clock, and will be output from
the SO terminal in order starting from the most significant bit. The data input from SI
terminal will be input to the least significant bit with the rising of the shift clock.
SIO Timing Chart
The above figure illustrates 8 bit communication. In 32 bit communication, the shift
clock sends and receives 32 bits of data.