Semiconductor Group
7-16
1997-10-01
Interrupt System
C541U
7.1.3 Interrupt Prioritiy Registers
Each interrupt source can also be individually programmed to one of two priority levels by setting or
clearing a bit in the SFRs IP0 or IP1 (interrupt priority: 0 = low priority, 1 = high priority).
Special Function Registers IP0 (Address B8H)
Reset Value : XXXX0000B
Special Function Registers IP1 (Address B9H)
Reset Value : XXXXX000B
Bit
Function
–
Reserved for future use.
PT1
Timer 1 overflow interrupt priority level
If PT1 = 0, the timer 1 interrupt has a low priority.
If PT1 = 1, the timer 1 interrupt has a high priority
PX1
External interrupt 1 priority level
If PX1 = 0, the external interrupt 1 has a low priority.
If PX1 = 1, the external interrupt 1 has a high priority.
PT0
Timer 0 overflow interrupt priority level
If PT0 = 0, the timer 0 interrupt has a low priority.
If PT0 = 1, the timer 0 interrupt has a high priority.
PX0
External interrupt 0 priority level
If PX0 = 0, the external interrupt 0 has a low priority.
If PX0 = 1, the external interrupt 0 has a high priority.
PUDI
USB device interrupt priority level
If PUDI = 0, the USB device interrupt has a low priority.
If PUDI = 1, the USB device interrupt has a high priority.
PUEI
USB endpoint interrupt priority level
If PUEI = 0, the USB endpoint interrupt has a low priority.
If PUEI = 1, the USB endpoint interrupt has a high priority.
PSSC
SSC interrupt priority level
If PSSC = 0, the SSC interrupt has a low priority.
If PSSC = 1, the SSC interrupt has a high priority.
MSB
LSB
IP0
–
–
–
–
PT1
PX1
PT0
PX0
7
6
5
4
3
2
1
0
Bit No.
B8H
IP1
–
–
–
–
–
PUDI
PUEI
PSSC
B9H
Summary of Contents for C541U
Page 1: ... 8 LW 026 0LFURFRQWUROOHU 8VHU V 0DQXDO http www siem ens d Sem iconductor ...
Page 7: ......
Page 21: ...Semiconductor Group 2 6 1997 10 01 Fundamental Structure C541U ...
Page 37: ...Semiconductor Group 4 6 1997 10 01 External Bus Interface C541U ...
Page 133: ...Semiconductor Group 6 88 1999 04 01 On Chip Peripheral Components C541U ...
Page 163: ...Semiconductor Group 8 8 1997 10 01 Fail Safe Mechanisms C541U ...
Page 185: ...Semiconductor Group 10 14 1997 10 01 OTP Memory Operation C541U ...