pca9622 NXP Semiconductors, pca9622 Datasheet - Page 16

• Manufacturer Part Number: pca9622
• Description: 16-bit Fm+ I2c-bus 100 Ma 40 V Led Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA9622_1
Product data sheet
7.5 Power-on reset
7.6 Software reset
When power is applied to V
condition until V
PCA9622 registers and I
zeroes) causing all the channels to be deselected. Thereafter, V
0.2 V to reset the device.
The Software Reset Call (SWRST Call) allows all the devices in the I
the power-up state value through a specific formatted I
correctly, it implies that the I
bus.
The SWRST Call function is defined as the following:
The I
a ‘SWRST Call Abort’. The PCA9622 does not initiate a reset of its registers. This
happens only when the format of the SWRST Call sequence is not correct.
1. A START command is sent by the I
2. The reserved SWRST I
3. The PCA9622 device(s) acknowledge(s) after seeing the SWRST Call address
4. Once the SWRST Call address has been sent and acknowledged, the master sends
5. Once the right 2 bytes (SWRST data byte 1 and byte 2 only) have been sent and
sent by the I
‘0000 0110’ (06h) only. If the R/W bit is set to ‘1’ (read), no acknowledge is returned to
the I
2 bytes with 2 specific values (SWRST data byte 1 and byte 2):
a. Byte 1 = A5h: the PCA9622 acknowledges this value only. If byte 1 is not equal to
b. Byte 2 = 5Ah: the PCA9622 acknowledges this value only. If byte 2 is not equal to
If more than 2 bytes of data are sent, the PCA9622 does not acknowledge any more.
correctly acknowledged, the master sends a STOP command to end the SWRST Call:
the PCA9622 then resets to the default value (power-up value) and is ready to be
addressed again within the specified bus free time (t
2
C-bus master must interpret a non-acknowledge from the PCA9622 (at any time) as
A5h, the PCA9622 does not acknowledge it.
5Ah, then the PCA9622 does not acknowledge it.
2
C-bus master.
DD
2
C-bus master.
has reached V
Rev. 01 — 27 March 2009
2
C-bus state machine are initialized to their default states (all
2
DD
2
C-bus address ‘0000 011’ with the R/W bit set to ‘0’ (write) is
C-bus is functional and that there is no device hanging the
, an internal power-on reset holds the PCA9622 in a reset
POR
. At this point, the reset condition is released and the
2
C-bus master.
16-bit Fm+ I
2
C-bus command. To be performed
2
BUF
C-bus 100 mA 40 V LED driver
).
DD
must be lowered below
2
C-bus to be reset to
PCA9622
© NXP B.V. 2009. All rights reserved.
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