USBIO24 ELEXOL, USBIO24 Datasheet - Page 7

• Manufacturer Part Number: USBIO24
• Description: DIGITAL I/O MODULE, USB TO 24 I/O
• Manufacturer: ELEXOL
• Type: USB I/O Moduler

Specifications of USBIO24

• Development Tool Type: Digital I/O Module
• Tool / Board Application: Digital Signal Transfer
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SPI Interface
Send / Receive SPI Byte on PORT A
Send / Receive SPI Byte on PORT B
Send / Receive SPI Byte on PORT C
Notes on SPI
Bit 1 is always Clock and must be set as an output from the SPI to function
Bit 2 is always Serial Data Out (MOSI) and must be set as an output from the SPI to function
Bit 3 is always Serial Data In (MISO) and must be set as an input from the SPI to function
All other port pins act as normal
Setting the port pin as high or low will set the clock as normally high or low before the SPI
transaction begins.
Any of the other pins can be used as SS or CE when SPI is used.
NOTE: This interface will not work with the 50MHz upgrade.
Setting up SPI
1. Set bit 3 for input (Serial Input) rest of port pins output
2. Sending bytes out via SPI
For every byte that is sent out via SPI it requires and "S" prefix. If you wanted to send out the
following bytes $FF $AA $55 you would do the following
3. Each byte returned from the SPI will have a preceding "S" character and then the byte value from
the SPI device.
Elexol Pty Ltd
COMMAND
COMMAND
COMMAND
example for VCP MSComm1.Output = "!A" + Chr$(4)
MSComm1.Output = "S" + Chr$(255) //S FF
MSComm1.Output = "S" + Chr$(170) //S AA
MSComm1.Output = "S" + Chr$(85)
‘U’
‘S’
‘T’
1 Byte of data sent on
SPI Bus
1 Byte of data sent on
SPI Bus
1 Byte of data sent on
SPI Bus
Version 1.1
DATA
DATA
DATA
Page 7
1 Byte of data received on
SPI Bus
1 Byte of data received on
SPI Bus
1 Byte of data received on
SPI Bus
//S 55
USB I/O 24 R Datasheet
REPLY
REPLY
REPLY
http://www.elexol.com
Send / Receive SPI
Byte on PORT C
Send / Receive SPI
Byte on PORT A
Send / Receive SPI
Byte on PORT B
FUNCTION
FUNCTION
FUNCTION