www.austriamicrosystems.com

Revision 1.00

11 - 17

AS1507

Data Sheet - D e t a i l e d D e s c r i p t i o n

Commands

Write Wiper Register

This is a 16-bit command (see Figure 22 on page 12). The first byte represents the command word starting with the

MSB bit of the command, the second byte represents the data written to the wiper register (starting with the MSB).

Data 0000 0000 the wiper moves the closest position to LOW, with data 1111 1111 the wiper moves to the closest posi-

tion to HIGH. The wiper registers can be written independently in two write cycles with different data or in one write

cycle with the same data.

Note: At power-up the wiper position stored in the non-volatile memory are automatically loaded into the wiper regis-

ter, the wiper moves to the related position.

Write to Non-Volatile Register

This is a 16-bit command (see Figure 22 on page 12). The first byte represents the command word starting with the

MSB bit of the command, the second byte represents the data written to the non-volatile memory. The wiper position is

not changed by this command, since the wiper register is not affected. The non-volatile registers can be written inde-

pendently in two write cycles with different data or in one write cycle with the same data.

There is a write non-volatile register time defined in the timing specification, which is required for storing the data in the

non-volatile register. The READY pin indicates the write time with an active-low signal. During this time the device

must not be powered down, otherwise the data stored in the non-volatile register is corrupted.

Copy Wiper Register to Non-Volatile Register

This command can be implemented as an 8- or 16-bit command. The data stored in the wiper register are transferred

to the non-volatile memory, to keep the data during power-down. There is no automatic trigger of this command during

power-down of the device. This command must be triggered before powering down the device.

There is a write non-volatile register time defined in the timing specification, which is required for storing the data in the

non-volatile register. During this time the device must not be powered down, otherwise the data stored in the non-vola-

tile register is corrupted.

Copy Non-Volatile Register to Wiper Register

This command can be implemented as an 8- or 16-bit command. The data stored in the non-volatile register are trans-

ferred to the wiper register, the wiper register moves to the stored position. This command is automatically executed

during power up of the system.

Read Non-Volatile Register

The AS1507 features the capability to read the data from the non-volatile register via the SPI interface (see Figure 23

on page 12). This command can be implemented as an 8- or 16-bit command. The SDIO pin is a bi-directional pin.

During the CSN low phase of the sequence the SDIO pin is used as input pin to set the command byte. After CSN ris-

ing edge the pin SDIO is set as output pin, the data stored in the non-volatile register are read serially, MSB first.

The data propagation starts at the second rising edge of SCLK after the rising edge of CSN. CSN must be high during

the read operation. With the next falling edge of CSN the SDIO pin is set to an input pin again.

Read Wiper Register

The AS1507 features the capability to read the data from the wiper register via the SPI interface (see Figure 23 on

page 12). This command can be implemented as an 8- or 16-bit command. The SDIO pin is a bi-directional pin. During

the CSN low phase of the sequence, the SDIO pin is used as input pin to set the command byte. After CSN rising edge

the pin SDIO is set as output pin, the data stored in the wiper register are read serially, MSB first. The wiper position is

unchanged.

The data propagation starts at the second rising edge of SCLK after the rising edge of CSN. CSN must be high during

the read operation. With the next falling edge of CSN the SDIO pin is set to an input pin again.

Mute Command

When a high signal is applied on the MUTE pin both wiper positions are set to zero permanently. While in mute opera-

tion SPI commands to wiper registers are not executed. Data stored in non-volatile registers are not affected by the

mute command. The MUTE pin includes a pull-down resistor. If a mute function is not required the pin can be left

unconnected.