Select High Speed or Normal Speed Mode

  The JP1 is used to select high speed mode or normal speed mode of port 1 and the JP2 is used to select high speed mode or normal speed mode of port 2; the clock is 7.3728MHZ for high speed mode, and 1.8432MHZ for normal speed mode. For high speed mode, the baud rate speed up to 460K. 

Pin

Clock Rate

Mode

Short 1,2

1.8432MHZ

Normal Speed

Short 2,3

7.3728MHZ

High Speed