Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 133

AGB Programming Manual
Normal Serial Communication Flow(Example)
Select internal clock with
Register SIOCNT and
select Cable Communication
256KHz or Special Hardware
2MHz for the frequency.
No
Is (d02) in Register
SIOCNT, (0)?
Set start flag for Register
Transmit(Receive/Send)
©1999 - 2001 Nintendo of America Inc.
Set (0) in (d15) of
Register RCNT
Set (0,0) or (0,1) in (d05,d04)
of Control Register SIOCNT
Set transfer data
Set (1) in (d03) of Control
Register SIOCNT
Yes
Communicate as the Master?
Yes
SIOCNT
Start Flag for Register
SIOCNT is reset. If the
Interrrupt Request Enable
Flag is set, an interrupt
End
request is generated
No
Select external clock with
Register SIOCNT
Set (0) in (d03) of Register
SIOCNT
Set Start Flag for Register
SIOCNT and wait for
external clock input
Transmit(Receive/Send)
End
133
Communication Functions
D.C.N. AGB-06-0001-002B4