UART Interface¶
The IMX has different UART TTL serial ports. These serial ports can be converted from TTL to RS232 or RS422 using a level converter, such as found on the Rugged-3, EVB-1, and EVB-2 carrier boards.
Actual UART Baud Rates¶
The serial ports use different peripherals so the actual baud rates of the ports differ.
Due to UART limitations, the actual baud rate that the hardware is capable of generating differs from the target or desired baud rate. This difference is more pronounced at higher baud rates (>921600 bps). The following table outlines these differences.
| Target Baud Rate (bps) | IMX-5 Actual Baud Rate (bps) |
uINS-3 Actual Baud Rate (bps) |
|---|---|---|
| 19,200 | 19,198 | 19,191 |
| 38,400 | 38,406 | 38,422 |
| 57,600 | 57,595 | 57,515 |
| 115,200 | 115,273 | 115,030 |
| 230,400 | 230,547 | 231,481 |
| 460,800 | 459,770 | 457,317 |
| 921,600 | 919,540 | 937,500 |
| 3,200,000 | 3,125,000 | |
| 4,000,000 | 3,750,000 | |
| 5,000,000 | 4,687,500 | |
| 8,000,000 | 6,250,000 | |
| 10,000,000 | 9,375,000 |
IMX-5 UART Baud Rate Equation¶
The actual baud rate that the IMX-5 hardware is capable of generating is described in the following equation.
Baud rates <= 5 Mbps:
Divisor = floor( (80e6 + ((Target Baud Rate)/2)) / (Target Baud Rate) )
Actual Baud Rate = floor( 80e6 / Divisor )
Divisor = floor( (160e6 + ((Target Baud Rate)/2)) / (Target Baud Rate) )
Actual Baud Rate = floor( 160e6 / Divisor )
uINS-3 UART Baud Rate Equation¶
The actual baud rate that the IMX-5 hardware is capable of generating is described in the following equations.
Divisor = floor( (18750000 + ((Target Baud Rate)/2)) / (Target Baud Rate) )
Actual Baud Rate = floor( 18750000 / Divisor )