UPD168111 Datasheet, PDF (15/39 Pages) NEC – MICROSTEP DRIVER FOR DRIVING CAMERA LENS

µPD168111
NOTES ON TRANSMITTING DATA
• Basically, the input data is loaded when SCLK changes from “L” to “H” after LATCH has changed from “L” to “H”.
Data is transmitted in 16-bit units, and is determined when LATCH changes from “H” to “L”. Invalid data of less
than 16 bits is discarded.
• Data of different addresses can be input successively while LATCH = “H”.
• The access time can be shortened by updating only the necessary data after initialization has been performed.
If an address is not input, the previous value of that address is retained as the data.
• If the same address is input more than once while LATCH is “H”, the data that is input last is valid.
• If invalid data and correct data are input while LATCH is “H”, only the correct data is valid.
• If only LATCH is input, the data is not updated, and the driver holds the current status.
• Data that is transmitted during the start point wait and start point excitation wait periods is ignored.
• Data that is transmitted when the RESETB pin is “L” and the EN pin is “L” is ignored.
• As shown below, dummy data must be transmitted immediately after reset if SCLK = “H” while LATCH =
“L”.
LATCH
SCLK
SDATA
The dummy data is defined to be “data of all 0 at address 0”. Transmit the dummy data before transmitting the
correct data.
This operation is necessary only immediately after reset. Once the dummy data has been transmitted, it does not
have to be transmitted again until the next reset operation is performed or the power is turned off and then back on
again.
If SCLK = “L” while LATCH = “L”, the dummy data does not have to be transmitted immediately after reset.
However, there is no problem even if the dummy data is transmitted.
Data Sheet S15865EJ1V0DS
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