MCP2030A Datasheet, PDF (50/74 Pages) Microchip Technology – Three-Channel Analog Front-End Devicewith 1 mVPP Input Detection Sensitivity

MCP2030A
5.31 Configuration Registers
5.31.1 SPI COMMUNICATION
The SPI communication is used to read from or write to
the Configuration registers and to send command-only
messages. Three pins are used for SPI
communication: CS, SCLK/ALERT, and
LFDATA/RSSI/CCLK/SDIO. Figure 5-9, Figure 5-10
and Figure 5-11 show examples of the SPI
communication sequences.
When these pins are connected to the external MCU
I/O pins, the following are needed:
CS
• Pin is permanently an input with an internal pull-up
SCLK/ALERT
• Pin is an open collector output when CS is high.
An internal pull-up resistor exists to ensure no
spurious SPI communication between powering
and the MCU configuring its pins. This pin
becomes the SPI clock input when CS is low
LFDATA/CCLK/SDIO
• Pin is a digital output (LFDATA) so long as CS is
high. During SPI communication, the pin is the
SPI data input (SDI) unless performing a register
Read, where it will be the SPI data output (SDO).
CS
SCLK/ALERT
ALERT
(open collector
output)
LFDATA/CCLK/SDIO
LFDATA
(output)
FIGURE 5-9:
Power-Up Sequence.
DS22235B-page 50
 2011 Microchip Technology Inc.