Rainbow Electronics AT89C5122 - Manual (Page 82)

82
AT8xC5122/23
4202E–SCR–06/06
Reset Value = 0X00 0000b
Note: 1) In case of multiple interrupts occuring at the same time (sampled by the same edge of
the internal clock), the interrupts will be serviced in the following order from the highest to
the lowest priority :
-
UART Transmit Buffer Empty
- Card Current Overflow
- Card Voltage Error
- Waiting Time Counter Timeout
- UART Transmitted Character
- UART Received Character
- Character Reception Parity Error
2) It is recommended that the application saves the SCIIR register after reading it in
order to avoid the loss of pending interruptions as the SCIIR register is cleared when it is
read by the MCU.
Table 47. Smart Card UART Interrupt Identification Register (Read Only)
SCIIR (S:AEh, SCRS=0)
7 6 5 4 3 2 1 0
SCTBI - ICARDERR VCARDERR SCWTI SCTI SCRI SCPI
Bit Number Bit Mnemonic Description
7 SCTBI
UART Transmit Buffer Empty Interrupt
This bit is set by hardware when the Transmit Buffer is copied into the transmit shift register of the Smart
Card UART. It generates an interrupt if ESCTBI bit is set in SCIER register otherwise this bit is irrelevant.
It is cleared by hardware when this register is read.
6 -
Reserved
The value read from this bit is indeterminate. Do not change this bit.
5 ICARDERR
Card Current Overflow Interrupt
This bit is set when the current on card is above the limit specified by bit OVFADJ in DCCKPS register (Table
61 on page 94). It generates an interrupt if ICARDER bit is set in SCIER register otherwise this bit is
irrelevant.
It is cleared by hardware when this register is read.
4 VCARDERR
Card Voltage Error Interrupt
This bit is set when the output voltage goes out of the voltage range specified by VCARD field. It generates
an interrupt if EVCARDER bit is set in SCIER register otherwise this bit is irrelevant.
It is cleared by hardware when this register is read.
3 SCWTI
Waiting Time Counter Timeout Interrupt
This bit is set by hardware when the Waiting Time Counter has expired. It generates an interrupt if ESCWTI
bit is set in SCIER register otherwise this bit is irrelevant.
It is cleared by hardware when this register is read.
2 SCTI
UART Transmitted Character Interrupt
This bit is set by hardware when the Smart Card UART has completed the character transmission. It
generates an interrupt if ESCTI bit is set in SCIER register otherwise this bit is irrelevant.
It is cleared by hardware when this register is read.
1 SCRI
UART Received Character Interrupt
This bit is set by hardware when the Smart Card UART has completed the character reception. It generates
an interrupt if ESCRI bit is set in SCIER register otherwise this bit is irrelevant.
It is cleared by hardware when this register is read.
0 SCPI
Character Reception Parity Error Interrupt
This bit is set at the same time as SCTI or SCRI if a parity error is detected on the received character. It
generates an interrupt if ESCPI bit is set in SCIER register otherwise this bit is irrelevant.
It is cleared by hardware when this register is read.