logiUART

Supported baudrates are in range from 5 bps (bit per second) up to 3 Mbps. Programmable baudrate prescaler and programmable number of samples per bit allow settings of many different baudrates with very little deviation from standard baudrates.

Baudrate depends on input clock (SPLB_Clk if PLB register interface, OPB_Clk if OPB register interface or S_AXI_ACLK if AXI4-Lite interface is used) frequency and values written into baudrate (C_BAUDRATE_REG) and sample registers (C_SAMPLE_REG):

baudrate = f(MCLK)/(SAMPLE_REG+1)/(0xfffff-BAUDRATE_REG+1)

For example for baudrate of 115200 bps at MCLK frequency of 48 MHz values in registers has to be:
C_BAUDRATE_REG = 0x0fff75
C_SAMPLE_REG = 0x02

baudrate = 48MHz/3/(0xfffff-0xfff75+1)=115108, error = 0.08%

The most often used baudrates on clock frequency of 100 MHz are given in next table: