GMS81C2012/GMS81C2020
HYUNDAI MicroElectronics
14.2 The method of Serial I/O
ꢃ Select transmission/receiving mode
ꢆ 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.
Note: When external clock is used, the frequency should
be less than 1MHz and recommended duty is 50%.
ꢇ In case of receiving mode, the received data is acquired
by reading the SIOR.
ꢄ In case of sending mode, write data to be send to SIOR.
ꢅ Set SIOST to “1” to start serial transmission.
Note: If both transmission mode is selected and transmis-
sion is performed simultaneously it would be made error.
14.3 The Method to Test Correct Transmission
Serial I/O Interrupt
Service Routine
0
SIOSF
1
Abnormal
SE = 0
Write SIOM
0
SR
1
Overrun Error
Normal Operation
- SE : Interrupt Enable Register Low IENL(Bit3)
- SR : Interrupt Request Flag Register Low IRQL(Bit3)
Figure 14-5 Serial Method to Test Transmission
68
MAR. 2000 Ver 1.00
HYNIX [ HYNIX SEMICONDUCTOR ]
