Datasheet

DP83640
www.ti.com SNOSAY8E –SEPTEMBER 2007–REVISED APRIL 2013
10.5.11 PTP Event Status Register (PTP_ESTS), Page 4
This register provides Status for the Event Timestamp unit. Reading this register provides status for the
next Event Timestamp contained in the Event Data Register. If this register is 0, no Event Timestamp is
available in the Event Data Register. Reading this register will automatically move to the next Event in the
queue.
Table 10-49. PTP Event Status Register (PTP_ESTS), address 0x1E
Bit Bit Name Default Description
15:1 RESERVED 0000 0, RO Reserved: Writes ignored, Read as 0
1
10:8 EVNTS_MISSED 000, RO/SC Event Missed:
Indicates number of events have been missed prior to this timestamp for the
EVNT_NUM indicated. This count value will stick at 7 if more than 7 events are
missed.
7:6 EVNT_TS_LEN 00, RO/SC Event Timestamp Length:
Indicates length of the Timestamp field in 16-bit words minus 1. Although all fields
are available, this indicates how many of the fields contain data different from the
previous Event Timestamp. This allows software to avoid reading more significant
fields if they have not changed since the previous timestamp. This field is valid for
both single and multiple events. The following shows the number of least significant
fields which have new data for each setting of TS_LENGTH:
00 : One 16-bit field is new (Timestamp_ns[15:0])
01 : Two 16-bit fields are new
10 : Three 16-bit fields are new
11 : All four 16-bit fields are new
5 EVNT_RF 0, RO/SC Event Rise/Fall direction:
Indicates whether the event is a rise or falling event. If the MULT_EVNT bit is set to
1, this bit indicates the Rise/Fall direction for the event indicated by EVNT_NUM.
0 = Falling edge detected
1 = Rising edge detected
4:2 EVNT_NUM 000, RO/SC Event Number:
Indicates Event Timestamp Unit which detected an event. If the MULT_EVNT bit is
set to 0, this indicates the lowest event number captured. If events have been
missed prior to this timestamp, it indicates the lowest event number captured which
had at least one missed event.
1 MULT_EVNT 0, RO/SC Multiple Event Detect:
Indicates multiple events were detected at the same time. If multiple events are
detected, an extended event status field is available as the first data read from the
Event Data Register.
0 = Single event detected
1 = Multiple events detected
0 EVENT_DET 0, RO/SC PTP Event Detected:
Indicates an Event has been detected by one of the Event Timestamp Units.
10.5.12 PTP Event Data Register (PTP_EDATA), Page 4
This register provides a mechanism for reading the Event Timestamp and extended event status. If
present, the extended event status is read prior to reading the Event Timestamp. Presence of the
Extended Event Status field is indicated by the MULT_EVNT bit in the PTP Event Status Register. The
timestamp consists of four 16-bit fields. This register contains a valid timestamp if the PTP_ESTS register
indicates an Event Timestamp is available. Not all fields have to be read for each timestamp. For example,
if the EVNT_TS_LEN indicates the seconds field has not changed from the previous event, software may
skip that read. Reading the PTP_ESTS register will cause the device to move to the next available
timestamp.
The fields are read in the following order:
• Extended Event Status[15:0] (only available if PTP_ESTS indicates detection of multiple events)
• Timestamp_ns [15:0]
• Timestamp_ns[29:16] (upper 2 bits are always 0)
Copyright © 2007–2013, Texas Instruments Incorporated Register Block 117
Submit Documentation Feedback
Product Folder Links: DP83640