I.MX27 Datasheet, PDF (46/148 Pages) Freescale Semiconductor, Inc – Multimedia Applications Processor

Electrical Characteristics
1 _{Hysteresis mode is recommended for input with transition time greater than 25 ns.}
Table 15. AC Electrical Characteristics of Fast General I/O Pads
ID
Parameter
Symbol Test Condition Min Typical Max
PA1 Output Pad Transition Times (Max High)
tpr
25 pF
0.9
1.2
2.0
50 pF
1.7
2.4
4.0
Output Pad Transition Times (High)
tpr
25 pF
1.15
1.6
2.7
50 pF
2.3
3.1
5.3
Output Pad Transition Times (Normal)
— Maximum Input Transition Times¹
tpr
25 pF
1.7
2.4
4.0
50 pF
3.4
4.7
8.0
trm
—
—
—
25
Note:
1 _{Hysteresis mode is recommended for input with transition time greater than 25 ns.}
Units
ns
ns
ns
ns
Table 16. AC Electrical Characteristics of DDR I/O Pads
ID
Parameter
PA1 Output Pad Transition Times (DDR Drive)
Output Pad Transition Times (Max High)
Output Pad Transition Times (High)
Output Pad Transition Times (Normal)
— Maximum Input Transition Times
Symbol Test Condition Min Typical Max Units
tpr
25 pF
0.5
0.75
1.2
ns
50 pF
1.0
1.45
2.4
tpr
25 pF
0.67
1.0
1.6
ns
50 pF
1.3
2.0
3.1
tpr
25 pF
1.0
1.5
2.4
ns
35 pF
1.95
2.9
4.7
tpr
25 pF
2.0
2.9
4.8
ns
50 pF
3.9
5.9
8.4
trm
—
—
—
5
ns
4.2.2 1-Wire Electrical Specifications
Figure 4 depicts the RPP timing, and Table 17 lists the RPP timing parameters.
One-Wire bus
(BATT_LINE)
1-Wire Tx
“Reset Pulse”
DS2502 Tx
“Presence Pulse”
OW2
OW1
OW3
OW4
Figure 4. Reset and Presence Pulses (RPP) Timing Diagram
i.MX27 and i.MX27L Data Sheet, Rev. 1.5
46
Freescale Semiconductor