AS3956 datasheet(61/109 Pages) AMSCO

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ams Datasheet

Page 61

[v1-10] 2018-Apr-27

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AS3956 − Detailed Description

MISO output is usually in tristate and it is only driven when

output data is available. MOSI and MISO can then be externally

shorted to create a bidirectional signal. When MISO output is

in tristate, it is possible to switch on a pull down resistor RPD

by activating option bit miso_pd1 in IO Configuration Register.

Figure 57:

IO Signals to Controller

Writing Data to Addressable Registers

(Register Write Mode)

Following figures show waveforms of writing a single byte and

writing multiple bytes with auto-incrementing address. After

the SPI operation mode bits, the address of starting register to

be written is provided. Then one or more data bytes are

transferred from the SPI, always MSB first. The data byte is

written in register on falling edge of its last clock. In case the

communication is terminated by putting /SS high before a

packet of 8 bits composing one byte is sent, writing of this

address does not exist or it is a read-only register, no write is

performed.

MOSI

MISO

MOSI

AS3956

MOSI

MISO

I/O

AS3956

Separate SPI Input and Output Signals to Controller

Bidirectional Data IO Signal to Controller

AS3956 Datasheet(PDF) 61 Page - ams AG