Accelerated Graphics Port Interface Specification

AGP3.0 Interface Specification
Rev. 1.0
81
Table 41: AGP3.0 AC Source-Synchronous Timing Parameters
8X Speed 4X Speed
Symbol Parameter Min Max Min Max Units Notes / Comments
Source Synchronous Transmitter
1
:
T
BIT_TIME/2
One half bit time 937.5 1875 ps
T
Dvb
Data valid before strobe 527.5 950 ps At the transmitter pads
T
Dva
Data valid after strobe 477.5 1150 ps At the transmitter pads
T
INTC_SUS
Strobe-to-data skew on
setup time caused by
interconnect effects
0 442.5 0 550 ps Includes (receiver) package
effects
T
INTC_HS
Strobe-to-data skew on
hold time caused by
interconnect effects
0 267.5 0 450 ps Includes (receiver) package
effects
T
TSf
CLK to first AD_STBF
rising edge
1.5 1.5 ns
T
TS8r
CLK to 4
th
AD_STBS
rising edge
19.5 19.5 ns
T
TR
, T
TF
Transmitter Rise, Fall
slew rate
2.0 3.5 1.5 3.5 V/ns See Table 42
T
R-F
Rise, Fall slew rate
matching deviation
25 25 %
Source Synchronous Receiver:
T
RX_SU
Receiver setup margin 0 85 0 400 ps Includes receiver induced
strobe-to-data skew on setup
margin
Includes effect with min/max
input slew rate (T
RR,
T
RF
) at
receiver pad (see note 2).
T
RX_H
Receiver hold margin 0 210 0 700 ps Includes receiver induced
strobe-to-data skew on hold
margin
Includes effect with min/max
input slew rate (T
RR,
T
RF
) at
receiver pad (see note 2).
T
RS8su
4
th
AD_STBS rising
edge before CLK
6 6 ns
T
RS8h
Receive strobe hold time
after CLK
0.5 0.5 ns
T
RR,
T
RF
Receiver Rise, Fall slew
rate
1 3.5 1 3.5 V/ns Need to characterize setup/hold
timing using input slew rate spec
at receiver pad