pdi1394l21 NXP Semiconductors, pdi1394l21 Datasheet - Page 24

• Manufacturer Part Number: pdi1394l21
• Description: 1394 Full Duplex Av Link Layer Controller
• Manufacturer: NXP Semiconductors

Philips Semiconductors
12.5.3 Interrupts
The PDI1394L21 provides a single interrupt line (HIF INT_N) for connection to a host controller. Status indications from four major areas of the
device are collected and ORed together to activate HIF INT_N. Status from four major areas of the device are collected in four status registers;
LNKPHYINTACK, ITXINTACK, IRXINTACK, and ASYINTACK. At this level, each individual status can be enabled to generate a chip-level
interrupt by activating HIF INT_N. To aid in determining the source of a chip-level interrupt, the major area of the device generating an interrupt
is indicated in the lower 4 bits of the GLOBCSR register. These bits are non-latching Read-Only status bits and do not need to be
acknowledged. To acknowledge and clear a standing interrupt, the bit in LNKPHYINTACK, ITXINTACK, IRXINTACK, or ASYINTACK causing
the interrupt status has to be written to a logic ‘1’; Note: Writing a value of ‘0’ to the bit has no effect.
12.5.3.1 Determining and Clearing Interrupts
When responding to an interrupt event generated by the PDI1394L21, or operating in polled mode, the first register examined is the GLOBCSR
register. The least significant nibble contains interrupt status bits from general sections of the device; the link layer controller, the AV transmitter,
the AV receiver, and the asynchronous transceiver. The bits in GLOBCSR[3:0] are self clearing status bits. They represent the logical OR of all
the enabled interrupt status bits in their section of the AV Link Layer Controller.
Once an interrupt, or status is detected in GLOBCSR, the appropriate interrupt status register needs to be read, see the Interrupt Hierarchy
diagram for more detail. After all the interrupt indications are dealt with in the appropriate interrupt status register, the interrupt status indication
will automatically clear in the GLOBCSR.
All interrupt status bits in the various interrupt status registers are latching unless otherwise noted.
12.5.3.2 Interrupt Hierarchy
2000 Aug 24
1394 full duplex AV link layer controller
HIF INT_N
3 2 1 0
GLOBCSR (0x018)
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
10
18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Figure 24. Interrupt Hierarchy
9
8
9
8
7
7 6 5 4 3 2 1 0
6 5 4 3 2 1 0
24
ITXINTACK (0x02C)
IRXINTACK (0x04C)
ASYINTACK (0x0A0)
LNKPHYINTACK (0x008)
SV01076
PDI1394L21
Preliminary specification