Datasheet

93
AT89C51AC3
4383D–8051–02/08
Reset Value = 00X0 XXXXb
Not Bit addressable
4 MODF
Mode Fault
- Set by hardware to indicate that the SS pin is in inappropriate logic level (in both
master and slave modes).
- Cleared by hardware when reading SPSCR
When MODF error occurred:
- In slave mode: SPI interface ignores all transmitted data while SS remains high.
A new transmission is perform as soon as SS returns low.
- In master mode: SPI interface is disabled (SPEN=0, see description for SPEN
bit in SPCON register).
3 SPTE
Serial Peripheral Transmit register Empty
- Set by hardware when transmit register is empty (if needed, SPDAT can be
loaded with another data).
- Cleared by hardware when transmit register is full (no more data should be
loaded in SPDAT).
2 UARTM
Serial Peripheral UART mode
Set and cleared by software:
- Clear: Normal mode, data are transmitted MSB first (default)
- Set: UART mode, data are transmitted LSB first.
1 SPTEIE
Interrupt Enable for SPTE
Set and cleared by software:
- Set to enable SPTE interrupt generation (when SPTE goes high, an interrupt is
generated).
- Clear to disable SPTE interrupt generation
Caution: When SPTEIE is set no interrupt generation occurred when SPIF flag
goes high. To enable SPIF interrupt again, SPTEIE should be cleared.
0 MODFIE
Interrupt Enable for MODF
Set and cleared by software:
- Set to enable MODF interrupt generation
- Clear to disable MODF interrupt generation
Bit
Number
Bit
Mnemonic Description