HYUNDAI MicroElectronics
GMS81508B/16B/24B
13.3 The method of Serial I/O
1. Select transmission/receiving mode.
2. In case of sending mode, write data to be send to SIOR.
3. Set SIOST to “1” to start serial transmission.
4. The SIO interrupt is generated at the completion of SIO
and SIOSF is set to “1”. In SIO interrupt service routine,
correct transmission should be tested.
5. In case of receiving mode, the received data is acquired
by reading the SIOR.
Note:
When external clock is used, the frequency should
be less than 1MHz and recommended duty is 50%. If both
transmission mode is selected and transmission is per-
formed simultaneously it would be made error.
13.4 The Method to Test Correct Transmission
Serial I/O Interrupt
Service Routine
0
SIOSF
1
SE = 0
Abnormal
Write SIOM
SR
1
Normal Operation
0
Overrun Error
- SE: Interrupt Enable Register Low IENL(Bit3)
- SR: Interrupt Request Flag Register Low IRQL(Bit3)
Figure 13-4 Serial Method to Test Transmission
DEC. 1999 Ver 1.04
51
HYNIX [ HYNIX SEMICONDUCTOR ]
