F1240NBGI datasheet(17/35 Pages) RENESAS

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September 11, 2018

F1240 Datasheet

Programming

F1240 can be programmed using either the parallel or serial interface which is selectable via VMODE (pin 4). The serial mode is selected by

setting VMODE to a logic LOW and the parallel mode by floating VMODE or by setting VMODE to a logic HIGH.

Serial Mode

F1240 Serial Mode is selected by setting VMODE to a logic LOW. The serial interface is a 16 bit shift register made up of two words. The first

word is the address or channel word, which uses only 1 of 8 bits to select the channel that will be programmed. The second 8 bit word is the

Gain (or attenuation) word, which uses 6 bits to control the DSA state and one bit to enable or disable the channel.

When serial programming is used, all of the other parallel control input pins (3, 6-10, 25, 31, 32) can be left floating.

Table 8.

8-Bit SPI Address (Channel) Word Sequence

Data Bit

Symbol

Not Used

Channel Selection

Table 9.

Truth Table for Address (Channel) Control Word

(MSB)

(LSB)

Program Channel

Table 10. 8-Bit SPI Gain (Attenuation) Word Sequence

Data Bit

Symbol

Enable Bit

Attenuation 16 dB Control Bit

Attenuation 8 dB Control Bit

Attenuation 4 dB Control Bit

Attenuation 2 dB Control Bit

Attenuation 1 dB Control Bit

Attenuation 0.5 dB Control Bit

Not Used

F1240NBGI Datasheet(PDF) 17 Page - Renesas Technology Corp