mpc8560vt667jb Freescale Semiconductor, Inc, mpc8560vt667jb Datasheet - Page 94

• Manufacturer Part Number: mpc8560vt667jb
• Description: Mpc8560 Powerquicc Iii Integrated Communications Processor
• Manufacturer: Freescale Semiconductor, Inc

System Design Information
When data is held high, SW1 is closed (SW2 is open) and R
OV
other in value. Then, Z
The output impedance of the RapidIO port drivers targets 200-Ω differential resistance. 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
1 with an external precision differential termination resistor of value R
V
drive current is then I
Table 61
nominal OV
94
Note: Nominal supply voltages. See
Impedance
2
Differential
= 1/(1/R
DD
R
R
/2. R
N
P
summarizes the signal impedance targets. The driver impedance are targeted at minimum V
P
1
DD
then becomes the resistance of the pull-up devices. R
+ 1/R
, 105°C.
Local Bus, Ethernet, DUART, Control,
Configuration, Power Management
2
)) × I
source
0
MPC8560 Integrated Processor Hardware Specifications, Rev. 4.2
= (R
source
1
= V
= R
P
43 Target
43 Target
. Solving for the output impedance gives R
+ R
Table
1
source
Figure 59. Driver Impedance Measurement
/R
NA
Data
N
source
Table 61. Impedance Characteristics
)/2.
1, T
× I
j
.
source
= 105°C.
. Second, the output voltage is measured while driving logic
PCI/PCI-X
25 Target
25 Target
Pad
P
NA
R
R
is trimmed until the voltage at the pad equals
OV
OGND
N
P
DD
P
and R
SW2
SW1
DDR DRAM
20 Target
20 Target
term
NA
N
source
are designed to be close to each
. The measured voltage is
= R
200 Target
RapidIO
term
NA
NA
Freescale Semiconductor
× (V
Symbol
1
Z
/V
Z
Z
DIFF
0
0
2
– 1). The
Unit
W
W
W
DD
,