Electrical and Thermal Characteristics
5.2.3 IEEE Std. 1149.1 AC Timing Specifications
Table 10 provides the IEEE Std. 1149.1 (JTAG) AC timing specifications as defined in Figure 8 through
Figure 11.
Table 10. JTAG AC Timing Specifications (Independent of SYSCLK)1
At recommended operating conditions. See Table 4.
Parameter
Symbol
Min
Max
Unit
Notes
TCK frequency of operation
fTCLK
0
33.3
MHz
TCK cycle time
tTCLK
30
—
ns
TCK clock pulse width measured at 1.4 V
tJHJL
15
—
ns
TCK rise and fall times
tJR and tJF
—
2
ns
TRST assert time
tTRST
25
—
ns
2
Input setup times:
Boundary-scan data
TMS, TDI
tDVJH
4
tIVJH
0
ns
3
—
—
Input hold times:
Boundary-scan data
TMS, TDI
tDXJH
20
tIXJH
25
ns
3
—
—
Valid times:
Boundary-scan data
TDO
ns
4
tJLDV
4
20
tJLOV
4
25
Output hold times:
Boundary-scan data
TDO
ns
4
tJLDX
30
—
tJLOX
30
—
TCK to output high impedance:
Boundary-scan data
TDO
ns
4, 5
tJLDZ
3
19
tJLOZ
3
9
Notes:
1. All outputs are measured from the midpoint voltage of the falling/rising edge of TCLK to the midpoint of the signal in question.
The output timings are measured at the pins. All output timings assume a purely resistive 50-Ω load (see Figure 7).
Time-of-flight delays must be added for trace lengths, vias, and connectors in the system.
2. TRST is an asynchronous level sensitive signal. The time is for test purposes only.
3. Non-JTAG signal input timing with respect to TCK.
4. Non-JTAG signal output timing with respect to TCK.
5. Guaranteed by design and characterization.
MPC7448 RISC Microprocessor Hardware Specifications, Rev. 4
Freescale Semiconductor
21