MC68MH360RC25L Freescale Semiconductor, MC68MH360RC25L Datasheet - Page 113

• Manufacturer Part Number: MC68MH360RC25L
• Description: IC MPU QUICC 25MHZ 241-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68MH360RC25L

• Processor Type: M683xx 32-Bit
• Speed: 25MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 241-PGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

Using Table 8-2, estimations of bandwidth utilization may be made. To calculate the total
system load, add the CPM utilization from every channel together. Assuming
approximately linear performance versus frequency
simple ratios:
For example, since a 25-MHz Ethernet running at 22 Mbps consumes approximately 100%
of the bandwidth, what bandwidth does a 10-Mbps channel require?
The above equation shows the 10-Mbps channel requiring 45% of the CPM bandwidth.
More examples follow.
Ethernet
SMC transparent
SMC UART
QMC
Bisync
1
nonlinear behavior. However, for these calculations we assume linear scaling with frequency.
Most protocols’ performance is scalable linearly to frequency with the exception of Ethernet which has
Protocol
CPM Utiilization
FD = Full duplex, HD = Half duplex
Further examples are given in Appendix A of the MPC860
user’s manual.
Freescale Semiconductor, Inc.
Table 8-2. CPM Performance Table (Continued)
For More Information On This Product,
CPM Utilization
1 : 1.136 HD
1 : 16.67 FD
1 : 113.636 FD
1 : 11.90 FD
1: 16.67 FD
SCC Rate: Clock Frequency
Mbps: MHz
Go to: www.freescale.com
=
Chapter 8. Performance
-------------------------------------
max serial rate
serial rate
=
---------------------------------- -
max serial rate
NOTE
serial rate
1
22
1.5
0.220
2.1
1.5
25 MHz
1
Mbps
1
+
, the general problem reduces to taking
-------------------------------------
max serial rate
Maximum Serial Throughput
=
serial rate
29
1.98
0.290
2.8
1.98
10
----- -
22
33 MHz
Mbps
=
0.45
2
2
35
2.4
0.352
3.36
2.4
40 MHz
Mbps
44
3
0.440
4.2
3
50 MHz
Mbps