23 isochronous transmit interrupt event register – Texas Instruments TSB12LV26 User Manual
Page 58

4–20
4.23 Isochronous Transmit Interrupt Event Register
The isochronous transmit interrupt event set/clear register reflects the interrupt state of the isochronous transmit
contexts. An interrupt is generated on behalf of an isochronous transmit context if an OUTPUT_LAST* command
completes and its interrupt bits are set. Upon determining that the interrupt event register (OHCI offset 80h/84h, see
Section 4.21) isochTx (bit 6) interrupt has occurred, software can check this register to determine which context(s)
caused the interrupt. The interrupt bits are set by an asserting edge of the corresponding interrupt signal, or by writing
a 1 in the corresponding bit in the set register. The only mechanism to clear a bit in this register is to write a 1 to the
corresponding bit in the clear register. See Table 4–16 for a complete description of the register contents.
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Name
Isochronous transmit interrupt event
Type
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
Default
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Isochronous transmit interrupt event
Type
R
R
R
R
R
R
R
R
RSC
RSC
RSC
RSC
RSC
RSC
RSC
RSC
Default
0
0
0
0
0
0
0
0
X
X
X
X
X
X
X
X
Register:
Isochronous transmit interrupt event
Type:
Read/Set/Clear, Read-only
Offset:
90h
set register
94h
clear register [returns IsoXmitEvent and IsoXmitMask when read]
Default:
0000 00XXh
Table 4–16. Isochronous Transmit Interrupt Event Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
31–8
RSVD
R
Reserved. Bits 31–8 return 0s when read.
7
isoXmit7
RSC
Isochronous transmit channel 7 caused the interrupt event register bit 6 (isochTx) interrupt.
6
isoXmit6
RSC
Isochronous transmit channel 6 caused the interrupt event register bit 6 (isochTx) interrupt.
5
isoXmit5
RSC
Isochronous transmit channel 5 caused the interrupt event register bit 6 (isochTx) interrupt.
4
isoXmit4
RSC
Isochronous transmit channel 4 caused the interrupt event register bit 6 (isochTx) interrupt.
3
isoXmit3
RSC
Isochronous transmit channel 3 caused the interrupt event register bit 6 (isochTx) interrupt.
2
isoXmit2
RSC
Isochronous transmit channel 2 caused the interrupt event register bit 6 (isochTx) interrupt.
1
isoXmit1
RSC
Isochronous transmit channel 1 caused the interrupt event register bit 6 (isochTx) interrupt.
0
isoXmit0
RSC
Isochronous transmit channel 0 caused the interrupt event register bit 6 (isochTx) interrupt.