
OHCI Registers
173
September 2005
SCPS110
8.25 Isochronous Receive Interrupt Event Register
The isochronous receive interrupt event set/clear register reflects the interrupt state of the isochronous receive
contexts. An interrupt is generated on behalf of an isochronous receive context if an INPUT_* command
completes and its interrupt bits are set to 1b. Upon determining that the isochRx (bit 7) interrupt in the interrupt
event register at OHCI offset 80h/84h (see Section 8.21) has occurred, software can check this register to
determine which context(s) caused the interrupt. The interrupt bits are set to 1b by an asserting edge of the
corresponding interrupt signal or by writing a 1b in the corresponding bit in the set register. The only
mechanism to clear a bit in this register is to write a 1b to the corresponding bit in the clear register. See
Table 818 for a complete description of the register contents.
OHCI register offset:
A0h
set register
A4h
clear register [returns the contents of isochronous receive interrupt event
register bit-wise ANDed with the isochronous receive mask register when
read]
Register type:
Read/Set/Clear, Read-only
Default value:
0000 000Xh
BIT NUMBER
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RESET STATE
0
BIT NUMBER
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESET STATE
0
X
Table 818. Isochronous Receive Interrupt Event Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
314
RSVD
R
Reserved. Bits 314 return 000 0000h when read.
3
isoRecv3
RSC
Isochronous receive channel 3 caused the interrupt event register bit 7 (isochRx) interrupt.
2
isoRecv2
RSC
Isochronous receive channel 2 caused the interrupt event register bit 7 (isochRx) interrupt.
1
isoRecv1
RSC
Isochronous receive channel 1 caused the interrupt event register bit 7 (isochRx) interrupt.
0
isoRecv0
RSC
Isochronous receive channel 0 caused the interrupt event register bit 7 (isochRx) interrupt.
8.26 Isochronous Receive Interrupt Mask Register
The isochronous receive interrupt mask set/clear register enables the isochRx interrupt source on a
per-channel basis. Reads from either the set register or the clear register always return the contents of the
isochronous receive interrupt mask register. In all cases the enables for each interrupt event align with the
isochronous receive interrupt event register bits detailed in Table 818.
OHCI register offset:
A8h
set register
ACh
clear register
Register type:
Read/Set/Clear, Read-only
Default value:
0000 000Xh
BIT NUMBER
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RESET STATE
0
BIT NUMBER
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESET STATE
0
X