Datasheet

FDS 6531/6532 005 Data Sheet 71M6531D/F-71M6532D/F
Rev 2 33
Interrupt Enable
Interrupt Flag
Interrupt Description
Name
Location
Name
Location
EX4
SFR B8[3]
IEX4
SFR C0[3]
External interrupt 4
EX5
SFR B8[4]
IEX5
SFR C0[4]
External interrupt 5
EX6
SFR B8[5]
IEX6
SFR C0[5]
External interrupt 6
EX_XFER
2002[0]
IE_XFER
SFR E8[0]
XFER_BUSY interrupt (INT 6)
EX_RTC
2002[1]
IE_RTC
SFR E8[1]
RTC_1SEC interrupt (INT 6)
IEN_WD_NROVF
20B0[0]
WD_NROVF_FLAG
20B1[0]
WDT near overflow (INT 6)
IEN_SPI
20B0[4]
SPI_FLAG
20B1[4]
SPI Interface (INT2)
EX_FWCOL
2007[4]
IE_FWCOL0
SFR E8[3]
FWCOL0 interrupt (INT 2)
IE_FWCOL1
SFR E8[2]
FWCOL1 interrupt (INT 2)
EX_PLL
2007[5]
IE_PLLRISE
SFR E8[6]
PLL_OK rise interrupt (INT 4)
IE_PLLFALL
SFR E8[7]
PLL_OK fall interrupt (INT 4)
IE_WAKE
SFR E8[5]
AUTOWAKE flag
†
IE_PB
SFR E8[4]
PB flag
†
†
The AUTOWAKE and PB flag bits are shown in Table 31 because they behave similarly to interrupt flags,
even though they are not actually related to an interrupt. These bits are set by hardware when the MPU
wakes from a push button or wake timeout. The bits are reset by writing a zero. Note that the PB flag is
set whenever the PB is pushed, even if the part is already awake.
WD_NROVF_FLAG is set approximately 1 ms before a WDT reset occurs. The flag can be cleared by writ-
ing a zero to it and is automatically cleared by the falling edge of WAKE.
Interrupt Priority Level Structure
All interrupt sources are combined in groups, as shown in Table 32:
Table 32: Interrupt Priority Level Groups
Group
Group Members
0
External interrupt 0, Serial channel 1 interrupt
1
Timer 0 interrupt, External interrupt 2
2
External interrupt 1, External interrupt 3
3
Timer 1 interrupt, External interrupt 4
4
Serial channel 0 interrupt, External interrupt 5
5
External interrupt 6
Each group of interrupt sources can be programmed individually to one of four priority levels (as shown in
Table 33) by setting or clearing one bit in the SFR interrupt priority register IP0 and one in IP1 (Table 34).
If requests of the same priority level are received simultaneously, an internal polling sequence as shown
in Table 35 determines which request is serviced first.
Changing interrupt priorities while interrupts are enabled can easily cause software defects. It is best
to set the interrupt priority registers only once during initialization before interrupts are enabled.
Table 33: Interrupt Priority Levels
IP1[x]
IP0[x]
Priority Level
0
0
Level 0 (lowest)
0
1
Level 1
1
0
Level 2
1
1
Level 3 (highest)