MPC8358 FREESCALE [Freescale Semiconductor, Inc], MPC8358 Datasheet - Page 93

• Manufacturer Part Number: MPC8358
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

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
× (V
Table 77
nominal OV
24.6
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 HRESET is asserted however, these pins are treated as inputs. The value presented on these pins
while HRESET is asserted, is latched when HRESET deasserts, at which time the input receiver is disabled
Freescale Semiconductor
1
/V
MPC8358E PowerQUICC™ II Pro Processor Revision 2.1 PBGA Silicon Hardware Specifications, Rev. 1
2
summarizes the signal impedance targets. The driver impedance are targeted at minimum V
– 1). The drive current is then I
Configuration Pin Muxing
DD
Note: Nominal supply voltages. See
Impedance
Differential
, 105°C.
R
R
N
P
2
= 1/(1/R
Configuration, Power
Local Bus, Ethernet,
Figure 54. Driver Impedance Measurement
1
DUART, Control,
Data
+ 1/R
Management
Table 77. Impedance Characteristics
42 Target
42 Target
NA
2
)) × I
source
Table
source
1
= V
= R
1, T
. Solving for the output impedance gives R
1
J
source
/R
= 105°C.
25 Target
25 Target
source
PCI
NA
× I
Pad
.
R
source
R
OV
OGND
N
P
DD
DDR DRAM
. Second, the output voltage is measured
20 Target
20 Target
SW2
SW1
NA
Symbol
Z
Z
Z
DIFF
0
0
System Design Information
Unit
W
W
W
term
source
. The
= R
DD
term
93
,