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January 19, 2006
IDT 79RC32435
Figure 18 SPI AC Timing Waveform — Bit I/O Mode
Signal
Symbol Reference
Edge
266MHz
300MHz
350MHz
400MHz
Unit Condi-
tions
Timing
Diagram
Reference
Min
Max
Min
Max
Min
Max
Min
Max
EJTAG and JTAG
JTAG_TCK
Tper_16a
none
25.0
50.0
25.0
50.0
25.0
50.0
25.0
50.0
ns
Thigh_16a,
Tlow_16a
10.0
25.0
10.0
25.0
10.0
25.0
10.0
25.0
ns
JTAG_TMS1,
JTAG_TDI
1. The JTAG specification, IEEE 1149.1, recommends that both JTAG_TMS and EJTAG_TMS should be held at 1 while the signal applied at JTAG_TRST_N changes from 0 to 1.
Otherwise, a race may occur if JTAG_TRST_N is deasserted (going from low to high) on a rising edge of JTAG_TCK when either JTAG_TMS or EJTAG_TMS is low, because the
TAP controller might go to either the Run-Test/Idle state or stay in the Test-Logic-Reset state.
Tsu_16b
JTAG_TCK
rising
2.4
—
2.4
—
2.4
—
2.4
—
ns
Thld_16b
1.0
—
1.0
—
1.0
—
1.0
—
ns
JTAG_TDO
Tdo_16c
JTAG_TCK fall-
ing
—
11.3
—
11.3
—
11.3
—
11.3
ns
Tdz_16c2
2. The values for this symbol were determined by calculation, not by testing.
—
11.3
—
11.3
—
11.3
—
11.3
ns
JTAG_TRST_
N
none
25.0
—
25.0
—
25.0
—
25.0
—
ns
JTAG_TCK
rising
2.0
—
2.0
—
2.0
—
2.0
—
ns
Thld_6e
1.0
—
1.0
—
1.0
—
1.0
—
ns
Table 14 JTAG AC Timing Characteristics
SCK, SDI, SDO (input)
Tpw_15e