Altera 10-Gbps Ethernet MAC MegaCore Function Manual do Utilizador Página 140

  • Descarregar
  • Adicionar aos meus manuais
  • Imprimir
  • Página
    / 175
  • Índice
  • MARCADORES
  • Avaliado. / 5. Com base em avaliações de clientes
Vista de página 139
Chapter 9: Interface Signals 9–21
February 2014 Altera Corporation 10-Gbps Ethernet MAC MegaCore Function User Guide
Table 911 describes the TX egress timestamp interface signals for the IEEE 1588v2
feature.
rx_ingress_timestamp_64b_data
Output 64
Carries the ingress timestamp on the receive
datapath. Consists of 48-bit nanoseconds field
and 16-bit fractional nanoseconds field.
The MAC presents the timestamp for all receive
frames and asserts this signal in the same clock
cycle it asserts
rx_ingress_timestamp_64b_valid
.
rx_ingress_timestamp_64b_valid
Output 1
When asserted, this signal indicates that
rx_ingress_timestamp_64b_data
contains
valid timestamp.
For all receive frame, the MAC asserts this signal
in the same clock cycle it receives the start of
packet (
avalon_st_rx_startofpacket
is
asserted).
Table 9–10. IEEE 1588v2 RX Ingress Timestamp Interface Signals (Part 2 of 2)
Signal Direction Width Description
Table 9–11. IEEE 1588v2 TX Egress Timestamp Interface Signals (Part 1 of 2)
Signal Direction Width Description
tx_egress_timestamp_request_valid
Input 1
Assert this signal when a user-defined
tx_egress_timestamp
is required for a
transmit frame.
Assert this signal in the same clock cycle as the
start of packet
(
avalon_st_tx_startofpacket
is asserted).
tx_egress_timestamp_request_fingerprint
Input 1-16
Use this bus to specify fingerprint for the
user-defined
tx_egress_timestamp
. The
fingerprint is used to identify the user-defined
timestamp.
The signal width is determined by the
TSTAMP_FP_WIDTH parameter.
The value of this signal is mapped to
user_fingerprint
.
This signal is only valid when you assert
tx_egress_timestamp_request_valid
.
tx_egress_timestamp_96b_data
Output 96
A transmit interface signal. This signal requests
timestamp of frames on the TX path. The
timestamp is used to calculate the residence
time.
Consists of 48-bit seconds field, 32-bit
nanoseconds field, and 16-bit fractional
nanoseconds field.
Vista de página 139
1 2 ... 135 136 137 138 139 140 141 142 143 144 145 ... 174 175

Comentários a estes Manuais

Sem comentários