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AT32F435/437
Series Reference Manual
2022.11.11
Page 638
Rev 2.03
26.3.52 Ethernet PTP target time high register (EMAC_PTPTTH)
Target time second register and target time subsecond register are used to schedule an interrupt event
when the system time exceeds the value programmed in these registers.
Bit
Register
Reset value
Type
Description
Bit 31: 0
TTSR
0x0000 0000 rw
Target Time Seconds Register
This register stores the time value in seconds. When the
time stamp value equals or exceeds both target time
stamp registers, the MAC starts or stops PPS signal output
depending on the bit [6: 5] of the PPS control register. An
interrupt is generated if enabled.
26.3.53 Ethernet PTP target time low register (EMAC_PTPTTL)
Bit
Register
Reset value
Type
Description
Bit 31: 0
TTLR
0x0000 0000 rw
Target Timestamp Low Register
This register stores the time (signed) in nanoseconds.
When the value of the time stamp equals both target time
stamp registers, the MAC starts or stops PPS signal output
depending on the TRGTMODSEL0 (bit [6: 5]) of the PPS
control register. An interrupt is generated if enabled.
When the bit 9 (TSCTRLSSR) is set in the
MAC_PTPTSCTR register, the value of this field cannot
exceed the 0x3B9A_C9FF. The actual time that starts or
stops PPT signal output may have an error of up to 1
subsecond increment value.
26.3.54 Ethernet PTP time stamp status register
(EMAC_PTPTSSR)
Bit
Register
Reset value
Type
Description
Bit 31: 2
Reserved
0x0000 0000 resd
Kept at its default value.
Bit 1
TTTR
0x0
ro
Timestamp Target Time Reached
When this bit is set, it indicates the value programmed
when the system time equals or exceeds the target time
second register and target time nanosecond register.
Bit 0
TSO
0x0
ro
Timestamp Seconds Overflow
When this bit is set, it indicates that the time stamp value
(V2 format supported) overflows and has exceeded the
32’hFFFF_FFFF.
26.3.55 Ethernet PTP PPS register (EMAC_PTPPPSCR)
Bit
Register
Reset value
Type
Description
Bit 31: 4
Reserved
0x0000000
resd
Kept at its default value.
Bit 3: 0
POFC
0x0
rw
PPS0 Output Frequency Control
The output of this field depends on the emac_pps_sel bit
(bit 15 in the CRM_MISC2 register)
Emac_pps_sel=0:
0000: 1 Hz, use binary rollover control, pulse width is 125
ms; use digital rollover, pulse width is 100 ms
0001: 2 Hz, use binary rollover control, duty cycle is 50%
(digital rollover is not recommended)
0010: 4 Hz, se binary rollover control, duty cycle is 50%
(digital rollover is not recommended)
0011: 8 Hz, use binary rollover control, duty cycle is
50%(digital rollover is not recommended)
0100: 16 Hz, use binary rollover control, duty cycle is 50%
(digital rollover is not recommended)
1111: 32.768 kHz, use binary rollover control, duty cycle is
50% (digital rollover is not recommended)
Emac_pps_sel=1:
0000: 1 Hz, pulse width is one clk_ptp cycle
0001: For binary rollover, 2hz, duty cycle 50%; For digital