MSC8103M1100 Motorola / Freescale Semiconductor, MSC8103M1100 Datasheet - Page 111

• Manufacturer Part Number: MSC8103M1100
• Description: Network Processor, Networking Digital Signal Processor
• Manufacturer: Motorola / Freescale Semiconductor

Equation 2: P = C
To determine a total power dissipation in a specific application, you must add the power values derived
from the above set of equations to the value derived for I/O power consumption using the following
equation for each output pin:
Where: P = power in mW, C = load capacitance in pF, f = output switching frequency in MHz.
For an application in which external data memory is used in a 32-bit single bus mode and no other
outputs are active, the core runs at 200 MHz, the CPM runs at 100 MHz and the SIU runs at 50 MHz,
power dissipation is calculated as follows:
Assumptions:
• External data memory is accessed every second cycle with 10% of address pins switching.
• External data memory writes occurs once every eight cycles with 50% of data pins switching.
• Each address and data pin has a 30 pF total load at the pin.
• The application operates at
Since the address pins switch once at every second cycle, the address pins frequency is a quarter of the
bus frequency (that is, 25 MHz).
For the same reason the data pins frequency is 3.125 MHz.
Calculating internal power (from Table 2-5 values):
Maximum allowed ambient temperature is:
P
P
P
P
P
T
Data, HRD, HRW
CORE
CPM
SIU
INT
D
A
= P
= T
Total P
CLKOUT
Address
(50) = ((P
Pins
= P
(100) = ((P
INT
J
V
(200) = ((P
– (PD
CORE
DDH
I/O
+ P
2
(200) + P
I/O
SIU
CPM
= 438 + 67 = 505
f
JA
CORE
– P
)
switching
10
# of pins
– P
LSI
CPM
– P
–3
) / 100)
LCP
34
4
1
V
LCO
(100) + P
DDH
) / 200)
)/300)
Table 4-1. Power Dissipation
= 3.3 V.
50 + P
SIU
100 + P
200 + P
(50) = 234 + 163 + 41 = 438
LSI
30
30
30
C
= ((80 – 2) / 100)
LCP
LCO
= ((320 – 6) / 200)
=((350 – 3) / 300
V
3.3
3.3
3.3
DDH
2
2
2
2
50 + 2 = 41
3. 125
100 + 6 = 163
200 + 3 = 234
12.5
50
f
Power Considerations
10
10
10
10
–3
–3
–3
–3
Power in mW
16.25
34.75
16
67
4-3