Datasheet

DP83630
SNLS335B –OCTOBER 2010–REVISED APRIL 2013 www.ti.com
10.6.9 PTP Receive Configuration Register 3 (PTP_RXCFG3), Page 5
This register provides extended configuration for IEEE 1588 Receive Timestamp operation.
Table 10-60. PTP Receive Configuration Register 3 (PTP_RXCFG3), address 0x1C
Bit Bit Name Default Description
15:1 TS_MIN_IFG 1100, RW Minimum Inter-frame Gap:
2 When a Timestamp is appended to a PTP Message, the length of the packet may
get extended. This could reduce the Inter-frame Gap (IFG) between packets by as
much as 8 byte times (640 ns at 100 Mb). This field sets a minimum on the IFG
between packets in number of byte times. If the IFG is set larger than the actual
IFG, preamble bytes of the subsequent packet will get dropped. This value should
be set to the lowest possible value that the attached MAC can support.
11 ACC_UDP 0, RW Record Timestamp if UDP Checksum Error:
By default, Timestamps will be discarded for packets with UDP Checksum errors. If
this bit is set, then the Timestamp will be made available in the normal manner.
10 ACC_CRC 0, RW Record Timestamp if CRC Error:
By default, Timestamps will be discarded for packets with CRC errors. If this bit is
set, then the Timestamp will be made available in the normal manner.
9 TS_APPEND 0, RW Append Timestamp for L2:
For Layer 2 encapsulated PTP messages, if this bit is set, always append the
Timestamp to end of the PTP message rather than inserted in unused message
fields. This bit will be ignored if TS_INSERT is 0.
8 TS_INSERT 0, RW Enable Timestamp Insertion:
Enables Timestamp insertion into a packet containing a PTP Event Message. If this
bit is set, the Timestamp will not be available through the PTP Receive Timestamp
Register.
7:0 PTP_DOMAIN 0000 0000, RW PTP Domain:
Value of the PTP Message domainNumber field. If PTP_RXCFG0:DOMAIN_EN is
set to 1, the Receive Timestamp unit will only capture a Timestamp if the
domainNumber in the receive PTP message matches the value in this field. If the
DOMAIN_EN bit is set to 0, the domainNumber field will be ignored.
10.6.10 PTP Receive Configuration Register 4 (PTP_RXCFG4), Page 5
This register provides extended configuration for IEEE 1588 Receive Timestamp operation.
Table 10-61. PTP Receive Configuration Register 4 (PTP_RXCFG4), address 0x1D
Bit Bit Name Default Description
15 IPV4_UDP_MOD 0, RW Enable IPV4 UDP Modification:
When timestamp insertion is enabled, this bit controls how UDP checksums are
handled for IPV4 PTP event messages.
If set to a 0, the device will clear the UDP checksum. If a UDP checksum error is
detected the device will force a CRC error.
If set to a 1, the device will not clear the UDP checksum. Instead it will generate a 2-
byte value to correct the UDP checksum and append this immediately following the
PTP message. If an incoming UDP checksum error is detected, the device will
cause a UDP checksum error in the modified field. This function should only be used
if the incoming packets contain two extra bytes of UDP data following the PTP
message. This should not be enabled for systems using version 1 of the IEEE 1588
specification.
14 TS_SEC_EN 0, RW Enable Timestamp Seconds:
Setting this bit to a 1 enables inserting a seconds field when Timestamp Insertion is
enabled. If set to 0, only the nanoseconds portion of the Timestamp will be inserted
in the packet. This bit will be ignored if TS_INSERT is 0.
13:1 TS_SEC_LEN 00, RW Inserted Timestamp Seconds Length:
2 This field indicates the length of the Seconds field to be inserted in the PTP
message. This field will be ignored if TS_INSERT is 0 or if TS_SEC_EN is 0. The
mapping is as follows:
00 : Least Significant Byte only of Seconds field
01 : Two Least Significant Bytes of Seconds field
10 : Three Least Significant Bytes of Seconds field
11 : All four Bytes of Seconds field
124 Register Block Copyright © 2010–2013, Texas Instruments Incorporated
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