Texas Instruments PCI7611 DV and MPEG2 Timestamp Enhancements, 1. TI Extension Register Map, A9Ch

9 TI Extension Registers

The TI extension base address register provides a method of accessing memory-mapped TI extension registers. See Section 7.9, TI Extension Base Address Register, for register bit field details. See Table 9−1 for the TI extension register listing.

Table 9−1. TI Extension Register Map

REGISTER NAME	OFFSET
Reserved	00h−A7Fh
Isochronous Receive DV Enhancement Set	A80h
Isochronous Receive DV Enhancement Clear	A84h
Link Enhancement Control Set	A88h
Link Enhancement Control Clear	A8Ch
Isochronous Transmit Context 0 Timestamp Offset	A90h
Isochronous Transmit Context 1 Timestamp Offset	A94h
Isochronous Transmit Context 2 Timestamp Offset	A98h
Isochronous Transmit Context 3 Timestamp Offset	A9Ch
Isochronous Transmit Context 4 Timestamp Offset	AA0h
Isochronous Transmit Context 5 Timestamp Offset	AA4h
Isochronous Transmit Context 6 Timestamp Offset	AA8h
Isochronous Transmit Context 7 Timestamp Offset	AACh

9.1 DV and MPEG2 Timestamp Enhancements

The DV timestamp enhancements are enabled by bit 8 (enab_dv_ts) in the link enhancement control register located at PCI offset F4h and are aliased in TI extension register space at offset A88h (set) and A8Ch (clear).

The DV and MPEG transmit enhancements are enabled separately by bits in the link enhancement control register located in PCI configuration space at PCI offset F4h. The link enhancement control register is also aliased as a set/clear register in TI extension space at offset A88h (set) and A8Ch (clear).

Bit 8 (enab_dv_ts) of the link enhancement control register enables DV timestamp support. When enabled, the link calculates a timestamp based on the cycle timer and the timestamp offset register and substitutes it in the SYT field of the CIP once per DV frame.

Bit 10 (enab_mpeg_ts) of the link enhancement control register enables MPEG timestamp support. Two MPEG time stamp modes are supported. The default mode calculates an initial delta that is added to the calculated timestamp in addition to a user-defined offset. The initial offset is calculated as the difference in the intended transmit cycle count and the cycle count field of the timestamp in the first TSP of the MPEG2 stream. The use of the initial delta can be controlled by bit 31 (DisableInitialOffset) in the timestamp offset register (see Section 9.5).

The MPEG2 timestamp enhancements are enabled by bit 10 (enab_mpeg_ts) in the link enhancement control register located at PCI offset F4h and aliased in TI extension register space at offset A88h (set) and A8Ch (clear).

When bit 10 (enab_mpeg_ts) is set to 1, the hardware applies the timestamp enhancements to isochronous transmit packets that have the tag field equal to 01b in the isochronous packet header and a FMT field equal to 10h.

9−1