AC Electrical Characteristics
6
AC Electrical Characteristics
The following sections include illustrations and tables of clock diagrams, signals, and CPM outputs and
inputs for 66.67/83.33/100/133 MHz devices. Note that AC timings are based on a 50-pf load for MAX
Delay and 10-pf load for MIN delay. Typical output buffer impedances are shown in this table.
Table 9. Output Buffer Impedances
1
Output Buffers
60x bus
Memory controller
Parallel I/O
PCI
1
Typical Impedance (Ω)
45 or 27
2
45 or 27
2
45
27
These are typical values at 65° C. Impedance may vary by ±25% with
process and temperature.
2
Impedance value is selected through SIUMCR[20,21]. See the SoC
reference manual.
6.1
CPM AC Characteristics
Table 10. AC Characteristics for CPM Outputs
1
This table lists CPM output characteristics.
Spec Number
Characteristic
Max
Min
Maximum Delay
66
MHz
6
8
10
8
11
11
11
83
MHz
5.5
8
10
8
11
11
11
100
MHz
5.5
8
10
8
11
11
11
Value (ns)
Minimum Delay
66
MHz
0.5
2
0
2
2.5
0.5
0.5
83
MHz
0.5
2
0
2
2.5
0.5
0.5
100
MHz
0.5
2
0
2
2.5
0.5
0.5
133
MHz
0.5
2
0
2
2.5
0.5
0.5
133
MHz
5.5
8
10
8
11
11
11
sp36a sp37a FCC outputs—internal clock (NMSI)
sp36b sp37b FCC outputs—external clock (NMSI)
sp38a sp39a SCC/SMC/SPI/I2C outputs—internal clock (NMSI)
sp38b sp39b SCC/SMC/SPI/I2C outputs—external clock (NMSI)
sp40
sp42
sp41
sp43
TDM outputs/SI
TIMER/IDMA outputs
sp42a sp43a PIO outputs
1
Output specifications are measured from the 50% level of the rising edge of CLKIN to the 50% level of the signal. Timings are
measured at the pin.
MPC8272 PowerQUICC II Family Hardware Specifications, Rev. 3
18
Freescale Semiconductor
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
