Communication Interfaces; Communication Data Format; Usb Interface; Control Transfer - SIGNALCORE SC5312A User Manual

2 SC5312A & SC5313A Hardware Manual

5 Communication Interfaces

The SC5307A has a PXI express interface, while the SC5308A has 2 communication interfaces:
1. USB and SPI
2. USB and RS232
This section will examine the communication aspects of the product, focusing on data transfer to and
from the device on each interface. Although the registers are identical for all interfaces, there are subtle
differences in the implementation of the interfaces to transfer the data.

Communication Data Format

All data sent and received by all interfaces is sent as buffers of unsigned bytes. For example, to change RF
frequency of the device to 6 GHz we perform the following:
1. Frequency is sent in 1000
6,000,000,000,000 milli-Hertz.
2. This number can be represented by a 64-bit unsigned long, and in Hexadecimal is 0x 0000 0574
FBDE 6000. Only the least 6 bytes are needed to represent all frequencies allowable for this
device.
3. A byte data buffer needs to be 8 bytes for register RF_FREQUENCY (address 0x10), so the byte
array buffer to be sent would be:
[0x10][0x00][0x05][0x74][0xFB][0xDE][0x60][0x00]
The register address byte [0x10] is the first member of the buffer to be sent.

USB Interface

There are 2 transfer types for the USB interface.
•

Control transfer

•

Bulk transfer

Control Transfer
The USB control transfer parameters are:
ENDPOINT_IN
ENDPOINT_OUT
TYPE_VENDOR
RECIP_INTERFACE
Bulk Transfer
The USB bulk transfer parameters are:
ENDPOINT_IN
ENDPOINT_OUT
Rev 2.1 | SC5312A & SC5313A
th
of Hertz, so the data that represents the frequency is
0x80
0x00
0x40
0x01
0x83
0x04
User Manual SignalCore, Inc.