MC68MH360RC25L Freescale Semiconductor, MC68MH360RC25L Datasheet - Page 114

• 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: -

Example #1
A device is operating at 25 MHz. SCC1 runs 1x10-Mbps Ethernet in half duplex, SCC2
runs 1 x 2-Mbps HDLC, SCC3 runs 1 x 64-Kbps HDLC, SCC4 runs 1 x 9.6-Kbps UART
and SMC1 runs 1 x 38-Kbps SMC UART. The following equation applies:
This yields a percentage CPM utilization of 96% meaning the device can handle these
protocols at this frequency. Note the 9.6-Kbps UART link only requires 0.4% of the CPM
bandwidth, implying that in any configuration where there is free bandwidth that it will be
possible to run a low-rate UART link.
Example #2
A device operating at 25 MHz is required to run 24 channels at 64 Kbps in QMC mode with
an additional 2 HDLC channels operating at 128 Kbps each. The following equation
applies:
Example #3
The last example shows an application with 32 QMC channels and one additional 2-Mbps
HDLC channel. The following equation applies:
Since the result above is greater than 1, this configuration may not work at 25 MHz. If a 33-
MHz operation is used, CPM utilization will drop below 1, allowing the combination to be
supported. The following equation applies:
In general, a channel combination will work if the combined load is less than 1. The
equations are scalable to frequency with the exception of the nonlinear Ethernet protocol.
Taking Ethernet into account is difficult. Designers will need to benchmark performance
for results near 1.
10
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22
Freescale Semiconductor, Inc.
+
For More Information On This Product,
2
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8
2
-- -
8
2 0.128
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+
+
8
32 0.064
-------------------------
0.064
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2.4
1.22
Go to: www.freescale.com
2.1
+
+
24 0.064
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25
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33
QMC Supplement
0.0096
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2.4
=
2.1
=
1.22
0.92
+
=
0.038
------------ -
0.22
0.76
(will not work)
(<1)
=
0.96
( <1)
( <1)