Laptop User Manual
S3C2440A RISC MICROPROCESSOR     UART 
  11-15 
UART MODEM CONTROL REGISTER 
There are two UART MODEM control registers including UMCON0 and UMCON1 in the UART block. 
Register Address R/W  Description  Reset Value 
UMCON0  0x5000000C  R/W  UART channel 0 Modem control register  0x0 
UMCON1  0x5000400C  R/W  UART channel 1 Modem control register  0x0 
Reserved 0x5000800C - Reserved  Undef 
UMCONn Bit  Description  Initial State
Reserved  [7:5]  These bits must be 0's  00 
Auto Flow Control (AFC)  [4]  0 = Disable 1 = Enable  0 
Reserved  [3:1]  These bits must be 0's  00 
Request to Send  [0]  If AFC bit is enabled, this value will be ignored. In this case 
the S3C2440A will control nRTS automatically. 
If AFC bit is disabled, nRTS must be controlled by software. 
0 = 'H' level (Inactivate nRTS) 1 = 'L' level (Activate nRTS) 
0 
Note 
UART 2 does not support AFC function, because the S3C2440A has no nRTS2 and nCTS2. 










