MPC555
/
MPC556
TIME PROCESSOR UNIT 3
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
17-19
17.4.11 Channel Interrupt Status Register
The channel interrupt status register (CISR) contains one interrupt status flag per
channel. Time functions specify via microcode when an interrupt flag is set. Setting a
flag causes the TPU3 to make an interrupt service request if the corresponding CIER
bit is set. To clear a status flag, read CISR, then write a zero to the appropriate bit.
CISR is the only TPU3 register that can be accessed on a byte basis.
17.4.12 Link Register
LR —
Link Register
0x30 4022, 0x30 4422
Used for factory test only.
17.4.13 Service Grant Latch Register
SGLR
— Service Grant Latch Register
0x30 4024, 0x30 4424
Used for factory test only.
17.4.14 Decoded Channel Number Register
DCNR
— Decoded Channel Number Register
0x30 4026, 0x30 4426
Used for factory test only.
Table 17-15 Channel Priorities
CHx[1:0]
Service
Guaranteed Time Slots
00
Disabled
—
01
Low
1 out of 7
10
Middle
2 out of 7
11
High
4 out of 7
CISR —
Channel Interrupt Status Register
0x30 4020
0x30 4420
MSB
LSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CH 15 CH 14 CH 13 CH 12 CH 11 CH 10
CH 9
CH 8
CH 7
CH 6
CH 5
CH 4
CH 3
CH 2
CH 1
CH 0
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 17-16 CISR Bit Descriptions
Bit(s)
Name
Description
0:15
CH[15:0]
Channel interrupt status
0 = Channel interrupt not asserted
1 = Channel interrupt asserted
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Freescale Semiconductor, Inc.
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