UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
702 of 1269
NXP Semiconductors
UM10503
Chapter 26: LPC43xx Ethernet
26.6.22 Time stamp addend register
This register is used by the software to readjust the clock frequency linearly to match the
master clock frequency.
This register value is used only when the system time is configured for Fine Update mode
(TSCFUPDT bit in
). This register content is added to a 32-bit accumulator in
every clock cycle and the system time is updated whenever the accumulator overflows.
26.6.23 Target time seconds register
This register contains the higher 32 bits of time to be compared with the system time for
interrupt event generation.
The Target Time Seconds register, along with Target Time Nanoseconds register, are
used to schedule an interrupt event (TSTARGT bit in
when Advanced
Timestamping is enabled, or otherwise, TS interrupt bit in
) when the system
time exceeds the value programmed in these registers.
Table 554. System time nanoseconds update register (NANOSECONDSUPDATE, address
0x4001 0714) bit description
Bit
Symbol
Description
Reset
value
Access
30:0
TSSS
Time stamp sub seconds
The value in this field has the sub second representation
of time, with an accuracy of 0.46 nano-second. (When
TSCTRLSSR is set in the time stamp control register,
each bit represents 1 ns and the programmed value
should not exceed 0x3B9A_C9FF.)
0
R/W
31
ADDSUB Add or subtract time
When this bit is set, the time value is subtracted with the
contents of the update register. When this bit is reset,
the time value is added with the contents of the update
register.
0
R/W
Table 555. Time stamp addend register (ADDEND, address 0x4001 0718) bit description
Bit
Symbol
Description
Reset
value
Access
31:0
TSAR
Time stamp addend
This register indicates the 32-bit time value to be added
to the Accumulator register to achieve time
synchronization.
0
R/W
Table 556. Target time seconds register (TARGETSECONDS, address 0x4001 071C) bit
description
Bit
Symbol
Description
Reset
value
Access
31:0
TSTR
Target time seconds register
This register stores the time in seconds. When the time
stamp value matches or exceeds both Target Time
Stamp registers, the MAC, if enabled, generates an
interrupt.
0
R/W