mcf5407 Freescale Semiconductor, Inc, mcf5407 Datasheet - Page 481

• Manufacturer Part Number: mcf5407
• Description: Mcf5407 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

PCLK. Although either signal can be used as a clock reference, CLKIN leaves more room
to meet the bus specifications than BCLKO, which is generated as a phase-aligned signal
to CLKIN.
Figure 20-4 shows timings for the parameters listed in Table 20-5.
Figure 20-5 shows PSTCLK timings for parameters listed in Table 20-5.
Note: Input and output AC timing specifications are measured to CLKIN with a 50-pF load capacitance (not
including pin capacitance).
1
BCLKO
C1
C2
C3
C4
C5
C6
C7
C8
C9
CLKIN
The PLL low-frequency limit depends on the clock divide ratio chosen. See Table 20-4.
Num
C9
CLKIN cycle time
CLKIN rise time (0.5V to 2.4 V)
CLKIN fall time (2.4V to 0.5 V)
CLKIN duty cycle (at 1.5 V)
PSTCLK cycle time
PSTCLK duty cycle (at 1.5 V)
BCLKO cycle time
BCLKO duty cycle (at 1.5 V)
CLKIN to BCLKO
Table 20-5. Clock Timing Specification
C4
Chapter 20. Electrical Specifications
Characteristic
Figure 20-4. Clock Timing
C1
C4
C8
C7
C8
54 MHz CLKIN
18.5
12.3
18.5
Min
-1.5
—
—
40
40
45
C3
Note
Note
Note
Max
1.5
60
60
55
2
2
Clock Timing Specifications
1
1
1
C2
Units
nS
nS
nS
nS
nS
nS
%
%
%
20-5