MPC8308CVMADDA FREESCALE [Freescale Semiconductor, Inc], MPC8308CVMADDA Datasheet - Page 84
![no-image](/images/no-image-200.jpg)
MPC8308CVMADDA
Manufacturer Part Number
MPC8308CVMADDA
Description
MPC8308 PowerQUICC II Pro Processor Hardware Specification
Manufacturer
FREESCALE [Freescale Semiconductor, Inc]
Datasheet
1.MPC8308CVMADDA.pdf
(88 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
MPC8308CVMADDA
Manufacturer:
Freescale Semiconductor
Quantity:
10 000
System Design Information
The value of this resistance and the strength of the driver’s current source can be found by making two
measurements. First, the output voltage is measured while driving logic 1 without an external differential
termination resistor. The measured voltage is V
while driving logic 1 with an external precision differential termination resistor of value R
measured voltage is V
R
Table 60
nominal NV
23.6
The device provides the user with power-on configuration options which can be set through the use of
external pull-up or pull-down resistors of 4.7 KΩ on certain output pins (see customer visible
configuration pins). These pins are generally used as output only pins in normal operation.
While PORESET is asserted however, these pins are treated as inputs. The value presented on these pins
while PORESET is asserted, is latched when PORESET deasserts, at which time the input receiver is
disabled and the I/O circuit takes on its normal function. Careful board layout with stubless connections
to these pull-up/pull-down resistors coupled with the large value of the pull-up/pull-down resistor should
minimize the disruption of signal quality or speed for output pins thus configured.
84
term
× (V
summarizes the signal impedance targets. The driver impedance are targeted at minimum V
Note: Nominal supply voltages. See
Configuration Pin Muxing
Impedance
1
/V
DD
2
R
R
, 105°C.
N
P
– 1). The drive current is then I
MPC8308 PowerQUICC II Pro Processor Hardware Specification, Rev. 0
2
= (1/(1/R
Local Bus, Ethernet, DUART, Control,
Configuration, Power Management
Figure 55. Driver Impedance Measurement
Data
1
+ 1/R
Table 60. Impedance Characteristics
Table
2
42 Target
42 Target
)) × I
2, T
1
source
source
= R
j
= 105°C.
source
. Solving for the output impedance gives R
= V
1
× I
/R
Pad
R
source
R
source
NV
N
P
VSS
DD
. Second, the output voltage is measured
.
SW2
SW1
DDR DRAM
20 Target
20 Target
Symbol
Z
Z
0
0
Freescale Semiconductor
term
Unit
Ω
Ω
. The
source
=
DD
,