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SSD1905
Rev 1.3
10/2002
SOLOMON
47
Bit 3 and Bit 0
CV Pulse Force High (bit 3) and CV Pulse Enable (bit 0)
These bits control the LCVOUT pin and CV Pulse circuitry as Table 7-15 : CV Pulse
Control.
When LCVOUT is forced low or forced high it can be used as a general purpose
output.
Note
Bit 3 must be set to 0 and bit 0 must be set to 1 before initiating a new burst using the
CV Pulse Burst Start bit.
The CV Pulse circuitry is disabled when Power Saving Mode is enabled.
Table 7-15 : CV Pulse Control
Bit 3
0
Bit 0
1
Result
CV Pulse circuitry enabled
(controlled by REG[B1h] and REG[B2h])
LCVOUT forced low
LCVOUT forced high
0
1
0
x
x = don’t care
Bit 2
CV Pulse Burst Status
A “1” indicates a CV pulse burst is occurring. A “0” indicates no CV pulse burst is
occurring. Software should wait for this bit to clear before starting another burst.
CV Pulse Burst Start
A “1” in this bit initiates a single LCVOUT pulse burst. The number of clock pulses
generated is programmable from 1 to 256. The frequency of the pulses is the divided
CV Pulse source divided by 2, with 50/50 duty cycle. This bit should be cleared to 0 by
software before initiating a new burst.
Bit 1
Note
This bit has effect only if the CV Pulse Enable bit is 1.
PWM Clock / CV Pulse Configuration Register
7
6
REG[B1h]
0
Bit
5
4
3
2
1
PWM Clock
Divide
Select
Bit 3
RW
0
PWM Clock
Divide
Select
Bit 2
RW
0
PWM Clock
Divide
Select
Bit 1
RW
0
PWM Clock
Divide
Select
Bit 0
RW
0
CV Pulse
Divide
Select
Bit 2
RW
0
CV Pulse
Divide
Select
Bit 1
RW
0
CV Pulse
Divide
Select
Bit 0
RW
0
PWMCLK
Source
Select
Type
Reset
state
RW
0
Bits 7-4
PWM Clock Divide Select Bits [3:0]
The value of these bits represents the power of 2 by which the selected PWM clock
source is divided.
Note
This divided clock is further divided by 256 before it is output at LPWMOUT.
Table 7-16 : PWM Clock Divide Select Options
PWM Clock Divide Select Bits [3:0]
0h
1h
2h
3h
...
Ch
Dh-Fh
PWM Clock Divide Amount
1
2
4
8
...
4096
1