Datasheet

DP83640
SNOSAY8E –SEPTEMBER 2007–REVISED APRIL 2013 www.ti.com
10.5.8 PTP Write Checksum (PTP_WRCKSUM), Page 4
This register keeps a running one’s complement checksum of 16-bit write data values for Page 4 write
accesses. Clear the checksum on a read. Write data to this register or the read checksum register ARE
accumulated in the write checksum to allow cross checking. Read data from this register is accumulated in
the read checksum to allow cross checking. Checksums are not accumulated for PHY Control Frame
register accesses, but are cleared on management or PHY Control Frame reads.
Table 10-46. PTP Write Checksum (PTP_WRCKSUM), address 0x1B
Bit Bit Name Default Description
15:0 WR_CKSUM XXXX XXXX XXXX PTP Write Checksum.
XXXX, RO/ COR
10.5.9 PTP Transmit Timestamp Register (PTP_TXTS), Page 4
This register provides a mechanism for reading the Transmit Timestamp. The fields are read in the
following order:
• Timestamp_ns [15:0]
• Overflow_cnt[1:0], Timestamp_ns[29:16]
• Timestamp_sec[15:0]
• Timestamp_sec[31:16]
The Overflow_cnt value indicates if timestamps were dropped due to an overflow of the Transmit
Timestamp queue. The overflow counter will stick at a value of three if additional timestamps were missed.
Table 10-47. PTP Transmit Timestamp Register (PTP_TXTS), address 0x1C
Bit Bit Name Default Description
15:0 PTP_TX_TS 0000 0000 0000 PTP Transmit Timestamp:
0000, RO Reading this register will return the Transmit Timestamp in four 16-bit reads.
10.5.10 PTP Receive Timestamp Register (PTP_RXTS), Page 4
This register provides a mechanism for reading the Receive Timestamp and identification information. The
fields are read in the following order:
• Timestamp_ns [15:0]
• Overflow_cnt[1:0], Timestamp_ns[29:16]
• Timestamp_sec[15:0]
• Timestamp_sec[31:16]
• sequenceId[15:0]
• messageType[3:0], source_hash[11:0]
The Overflow_cnt value indicates if timestamps were dropped due to an overflow of the Transmit
Timestamp queue. The overflow counter will stick at a value of three if additional timestamps were missed.
Table 10-48. PTP Receive Timestamp Register (PTP_RXTS), address 0x1D
Bit Bit Name Default Description
15:0 PTP_RX_TS 0000 0000 0000 PTP Receive Timestamp:
0000, RO Reading this register will return the Receive Timestamp in four 16-bit reads.
116 Register Block Copyright © 2007–2013, Texas Instruments Incorporated
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