vsc055xkm-01 Maxim Integrated Products, Inc., vsc055xkm-01 Datasheet - Page 64

• Manufacturer Part Number: vsc055xkm-01
• Description: Enhanced I?c Backplane Controller
• Manufacturer: Maxim Integrated Products, Inc.

3.2.59 72h: Pulse Train Control 10 (PTC10)
Revision 4.1
January 2008
This register, along with the PTC11 register, provides a user-programmable LED flashing pulse train. The
user can adjust the pulse duration, the pulse train length, and the on/off time to derive a specific visual
indication. The PTC10 register provides eight of the twelve bits available in the programmable pulse train.
The PTC11 register contains two bits of pulse-width programmability, two bits of pulse train length
programmability, and the remaining four bits of the programmable pulse train.
As an example, the pulse train can be used to develop a visual heartbeat indication by programming the
PTC10 register with a 45h and the PTC11 register with a C1h. This combination develops a pulse train
with two blinks followed by a gap with the on times of the LED equal to 125 ms.
If the default values of this register or the PTC11 register are modified, and synchronization to other LED
flash rates is desired, the SYNC# pin must be enabled. To enable the SYNC# pin, tie the SYNCEN pin to
V
value in bits 3:0 of the Clock Select Control register. For information on the Clock Select Control register,
see
The following table shows the bit assignments for the Pulse Train Control 10 register.
Register Name:
Address:
Reset Value:
Bit
7:0
DD
“FDh: Clock Select Control (CSC),”
, connect an external 10 kΩ pull-up resistor to the SYNC# pin, and place the proper synchronization
Bit Label
PT7-0
PTC10
72h
0000_0000b
Access
R/W
Description
Pulse Train
These eight bits are the first bits shifted out from 0 to 7 and define the on/off
time for the flash rate.
1: defines LED on time
0: defines LED off time.
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VSC055-01
Data Sheet