National Semiconductor CP3BT26 User Manual page 138

19.10.12 CAN Interrupt Clear Register (CICLR)
The CICLR register bits individually clear CAN interrupt
pending flags caused by the message buffers and from the
Error Management Logic. Do not modify this register with in-
structions that access the register as a read-modify-write
operand, such as the bit manipulation instructions.
15 14
EICLR
EICLR The Error Interrupt Clear bit is used to clear
the EIPND bit.
0 – The EIPND bit is unaffected by writing 0.
1 – The EIPND bit is cleared by writing 1.
ICLR The Buffer Interrupt Clear bits are used to
clear the IPND bits.
0 – The corresponding IPND bit is unaffected
by writing 0.
0 – The corresponding IPND bit is cleared by
writing 1.
19.10.13 CAN Interrupt Code Enable Register (CICEN)
The CICEN register controls whether the interrupt pending
flag in the CIPND register is translated into the Interrupt
Code field of the CSTPND register. All interrupt requests,
CAN error, and message buffer interrupts can be enabled/
disabled separately for the interrupt code indication field.
15 14
EICEN
EICEN The Error Interrupt Code Enable bit controls
encoding for error interrupts.
0 – Error interrupt pending is not indicated in
the interrupt code.
1 – Error interrupt pending is indicated in the
interrupt code.
ICEN The Buffer Interrupt Code Enable bits control
encoding for message buffer interrupts.
0 – Message buffer interrupt pending is not
indicated in the interrupt code.
1 – Message buffer interrupt pending is indi-
cated in the interrupt code.
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ICLR
0
W
ICEN
0
R/W
19.10.14 CAN Status Pending Register (CSTPND)
The CSTPND register holds the status of the CAN Node
and the Interrupt Code.
15
Reserved
0
NS The CAN Node Status field indicates the sta-
tus of the CAN node as shown in Table 61.
NS
000
010
011
10X
11X
IRQ/IST The IRQ bit and IST field indicate the interrupt
source of the highest priority interrupt current-
ly pending and enabled in the CICEN register.
Table 62 shows the several interrupt codes
when the encoding for all interrupt sources is
enabled (CICEN = FFFFh).
Table 62 Highest Priority Interrupt Code
0
IRQ
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
138
8 7 5 4 3
NS IRQ
0
R
Table 61 CAN Node Status
Node Status
Not Active
Error Active
Error Warning Level
Error Passive
Bus Off
CAN Interrupt
IST3:0
Request
0000 No interrupt request
0000 Error interrupt
0001 Buffer 0
0010 Buffer 1
0011 Buffer 2
0100 Buffer 3
0101 Buffer 4
0110 Buffer 5
0111 Buffer 6
1000 Buffer 7
1001 Buffer 8
1010 Buffer 9
1011 Buffer 10
1100 Buffer 11
1101 Buffer 12
1110 Buffer 13
1111 Buffer 14
0
IST