
February 2014 Altera Corporation 10-Gbps Ethernet MAC MegaCore Function User Guide
B. Time-of-Day (ToD) Clock
The ToD clock provides a stream of timestamps for the IEEE 1588v2 feature.
B.1. Features
■ Provides a stream of 96-bit timestamps. The timestamp has 48-bit second field,
32-bit nanosecond field, and 16-bit fractional nanosecond field.
■ Runs at 156.25 MHz for the 10GbE MAC IP core.
■ Supports coarse adjustment and fine adjustments through clean frequency
adjustment.
■ Supports period adjustment for frequency control using the
Period
register.
■ Supports offset adjustment using the
AdjustPeriod
register.
■ Automatically synchronizes to the master ToD clock through the ToD
synchronization module when connected.
■ Allows periodic correction if the ToD clock drifts from the actual time.
B.2. Device Family Support
Table B–1 shows the level of support offered by the ToD clock for each Altera device
family.
B.3. Performance and Resource Utilization
Table B–2 provides the estimated resource utilization and performance of the ToD
clock for the Stratix V device family.
Table B–1. Device Family Support
Device Family Support
Arria V GX/GT/GZ/SOC Preliminary
Cyclone V Preliminary
Stratix IV GX/GT Preliminary
Stratix V GX/GT Preliminary
Other device families No support
Table B–2. Stratix V Performance and Resource Utilization
MegaCore Function Settings
FIFO Buffer
Size
(Bits)
Combinational
ALUTs Logic Registers
Memory
(M20K Blocks/
MLAB Bits)
ToD Clock Default 0 378 1,120 0/0
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