MCP3901EV-MCU16 Microchip Technology, MCP3901EV-MCU16 Datasheet - Page 17

• Manufacturer Part Number: MCP3901EV-MCU16
• Description: BOARD EVAL FOR 2CH ADC MCP3901
• Manufacturer: Microchip Technology

Specifications of MCP3901EV-MCU16

• Number Of Adc's: 2
• Number Of Bits: 24
• Data Interface: SPI™
• Inputs Per Adc: 1 Differential
• Input Range: ±1 V
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: MCP3901
• Silicon Manufacturer: Microchip
• Application Sub Type: ADC
• Kit Application Type: Data Converter
• Silicon Core Number: MCP3901, PIC24F, PIC24H, DsPIC33, PIC18F86J55
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FIGURE 2-2:
© 2009 Microchip Technology Inc.
At the read of the last sample, read the Timer 8:9 content
Compute the 24-bit value for each channel and save it in
Send 12 transfers on the SPI to read the content of the 6
At the first sample read start timer 32 bit Timer 8:9;
registers that are holding the ADC result;
(for
Read Configuration High register;
Read Configuration Low register;
CS high. If the CCT was 0 then the data that comes from MCP3901 is ADC conversion
data and it will be converted from 3 bytes into an unsigned long number. This 24-bit
value will be saved into the current or voltage buffers.
When the first sample is written in the buffer, the 32-bit timer created using timer 8 and
9 start to count from 0. When the last sample is written into the buffer the 32-bit timer
is read. The value indicated will be used to compute the sampling speed.
If the CCT is 1, then the data read from the MCP3901 will be the configuration data.
This will be saved in MCU in other global variables, used later to send this info to PC
GUI.
After the completion of the SPI communication, the SPI interrupt will be disabled and
the UART TX interrupt will be enabled. The first char sent on UART is char 33; this is
the header of the UART communication protocol that is adopted here.
Read Modulator output register;
SPI Routine Flowchart.
sampling speed measurement);
Voltage and Current buffers;
Read Phase register;
Read Status register;
Read Gain register;
YES
Read Address Loop Bits from Status
Sent the char 0d33 on UART;
Enable UART TX interrupt;
SPI1 Transfer Interrupt
Disable SPI interrupt;
If Address Loop =
Exit SPI Interrupt
Read SPI1BUF;
Clear Flag;
Register ;
NONE?
At the read of the last sample, read the Timer 8:9 content
Compute the 24 bit value for each channel and save it in
Send 6 transfers on the SPI to read the content of the 6
At the first sample read start timer 32 bit Timer 8:9;
registers that are holding the ADC result;
(for
Read Configuration High register;
Read Configuration Low register;
sampling speed measurement);
Read Modulator output register;
Voltage and Current buffers;
Read Phase register;
Read Status register;
Read Gain register;
NO
Firmware
DS51845A-page 13