pca9901 NXP Semiconductors, pca9901 Datasheet - Page 6

• Manufacturer Part Number: pca9901
• Description: One Wire Single Led Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA9901_1
Product data sheet
8.2.1 TRAINING START command
8.2.2 TRAINING END command
8.2.3 RUN ONCE command
8.2.4 RUN command
8.2.5 STOP command
8.2 Command descriptions
2 pulses sent to the PCA9901 in less than 1.5 ms causes the PCA9901 to enter the
Training mode.
The PCA9901 leaves the Shutdown mode as soon as the 1
resets its registers to zeroes and is ready for sequence capture within the 1.5 ms.
The next assertion of the CTRL pin (LOW to HIGH transition) starts the first LED ON
period capture. CTRL cannot be asserted in less than 1.5 ms after the TRAINING START
command has been issued.
3 pulses sent to the PCA9901 in less than 1.5 ms causes the PCA9901 to leave the
Training mode.
The PCA9901 ends the last LED OFF period capture when the TRAINING END command
occurs.
The PCA9901 goes to Shutdown mode.
4 pulses sent to the PCA9901 in less than 1.5 ms causes the device to enter the
RUN ONCE mode and wait for a ‘synchronization’ rising edge on CTRL.
When a rising edge on CTRL is detected, the sequence that has been previously captured
is run once. If no sequence has been captured it will go into Shutdown mode.
Once the sequence has been run, the PCA9901 goes to Shutdown mode.
Remark: CTRL line may stay either HIGH or LOW after the ‘synchronization’ edge.
A LOW to HIGH transition followed by a HIGH state longer than 1.5 ms causes the
sequence that has been previously captured to be executed in loop. The CTRL pin stays
HIGH as long as the sequence is executed. If no sequence has been captured it will go
into Shutdown mode.
A HIGH to LOW transition when the PCA9901 is in the RUN mode causes the sequence
that is running to stop:
Once the sequence has been stopped, the PCA9901 goes to Shutdown mode.
•
•
Immediately, if the transition occurred during the LED OFF time
After finishing the execution of the current LED ON cycle if the transition occurred
during the LED ON time.
Rev. 01 — 3 December 2009
st
One wire single LED driver
rising edge is detected,
PCA9901
© NXP B.V. 2009. All rights reserved.
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