AV-51002
2015.12.16
1-91
Glossary
Term
Definition
Single-ended voltage referenced I/O
standard
The JEDEC standard for the SSTL and HSTL I/O defines both the AC and DC input signal values. The
AC values indicate the voltage levels at which the receiver must meet its timing specifications. The DC
values indicate the voltage levels at which the final logic state of the receiver is unambiguously defined.
After the receiver input has crossed the AC value, the receiver changes to the new logic state.
The new logic state is then maintained as long as the input stays beyond the DC threshold. This approach
is intended to provide predictable receiver timing in the presence of input waveform ringing.
Single-Ended Voltage Referenced I/O Standard
V CCIO
VOH
VIH AC
( )
VIH(DC )
V REF
V IL(DC )
V IL(AC
)
VOL
VSS
tC
High-speed receiver/transmitter input and output clock period.
TCCS (channel-to-channel-skew)
The timing difference between the fastest and slowest output edges, including the tCO variation and clock
skew, across channels driven by the same PLL. The clock is included in the TCCS measurement (refer to
the Timing Diagram figure under SW in this table).
tDUTY
High-speed I/O block—Duty cycle on high-speed transmitter output clock.
Arria V GX, GT, SX, and ST Device Datasheet
Send Feedback
Altera Corporation