Oki MSM9225B, User Manual

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MSM9225B User’s Manual
Chapter 2 Register Descriptions
2 – 29
(2) Output driver format setting: OCPOL, OCTN, OCTP
OCPOL is used to set the polarity of output.
OCTN is used to set the open drain mode of the Nch transistor of the output driver.
OCTP is used to set the open drain mode of the Pch transistor of the output driver.
Figure 2-26 shows the circuit configuration of the output driver, and Table 2-10 the relationship between
bit content and output driver format.
Output control
circuit
Output data
Synchronization
clock
V
DD
P
ch
Tx0
N
ch
GND
V
DD
P
ch
Tx1
N
ch
GND
Figure 2-28 Circuit Configuration of Output Driver
Table 2-10 Output Driver Format Setting
Mode OCTPn* OCTNn* OCPOLn*
Output
data
Pch Tr Nch Tr Txn* pin output level
0 off off Floating
0
1 off off Floating
0 off off Floating
Floating 0
1
1 off off Floating
0 off on “0”
0
1 off off Floating
0 off off Floating
Pull-down
0
1
1
1 off on “0”
0 off off Floating
0
1 on off “1”
0 on off “1”
Pull-up 0
1
1 off off Floating
0 off on “0”
0
1 on off “1”
0 on off “1”
Push-pull
1
1
1
1 off on “0”
* n = 0 or 1