ST18-AU1 STMICROELECTRONICS [STMicroelectronics], ST18-AU1 Datasheet - Page 37

• Manufacturer Part Number: ST18-AU1
• Description: SIX-CHANNEL DOLBY AC3/MPEG2 AUDIO DECODER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Figure 8.2
IMR: Interrupt mask/sensitivity register
(Address = 0029, Reset = 5555h, Read/Write))
Each interrupt input ITRQ0-7 can be masked individually when the corresponding IM0-7 bit is
set. In this case any activity on the ITRQ0-7 pin is ignored. All IM bits are set during DSP reset.
ITRQ0-7 is active either on a low level when IS0-7 is low (by default on reset) or on a falling
edge when IS0-7 is high.
When ITRQ0-7 is active on a low level, it must stay low until the ITACK falling edge is sampled.
Note, edge sensitive mode of operation must be set for all internal interrupt sources.
Bit
IM
IS
ICR
ISPR
IS7
15
SPL4 SPL3 SPL2 SPL1 ES CPL
X
IM7
14
X
PROGRAM
X
IS6
13
Function
Interrupt mask
Sensitivity
ICR and ISPR Operation
X
0: Interrupt is not masked
1: Interrupt is masked (default)
0: ITRQ is active on a low level (default)
1: ITRQ is active on a falling edge
IM6
12
1
ISP
-1
0
IT2
IS5
11
IM5
10
SPL4 SPL3 SPL2 SPL1 ES CPL
X
IS4
9
INTERRUPT LEVEL 2
X
PROGRAM IT2
IM4
8
X
-1
IS3
7
0
IM3
ISP
6
2
1
IT3
IS2
5
IM2
SPL4 SPL3 SPL2 SPL1 ES CPL
4
X
IS1
INTERRUPT LEVEL 3
3
X
PROGRAM IT3
-1
IM1
2
2
ST18-AU1
IS0
VR02020D
1
0
ISP
3
2
IM0
37/87
0