;******************************************************** ;* 2651 Usart Commmand And Status port equates * ;* File Name: U2651.EQU * ;* Last Update: 2/10/83 * ;******************************************************** ; usart's command registers bit equates X_CTL equ 01H ; Set enables Xmitter DTR equ 02H ; 1 forces the DTR pin low R_CTL equ 04H ; Set enables the Receiver ERROR_RESET equ 10H ; Setting this resets the error flags RTS equ 20H ; 1 forces the RTS pin low ; usart's status register bit equates TXRDY equ 01H ; Set = the Xmit buffer is empty RXRDY equ 02H ; Set = the Recv buffer has data PARITY_ERR equ 08H ; Set = parity error OVERRUN_ERR equ 10H ; Set = overrun error FRAME_ERR equ 20H ; Set = framing error DCD equ 40H ; Set means DCD is low DSR equ 80H ; Set means DSR is low