dcm44n.a51

8051实时操作系统

$TITLE (iDCM 44 COMMUNICATIONS FIRMWARE: SERIAL NON-AUTO MODULE)
$DATE (8 AUGUST 86)
$NOMO
$PAGING
$REGISTERBANK (0)

;***************************************************************************
;*
;*     TITLE:          iDCM 44 COMMUNICATIONS FIRMWARE: SERIAL NON-AUTO MODULE
;*
;*     RELEASE:        2.0
;*
;*     DESCRIPTION:    THIS MODULE CONTAINS THE SERIAL PROCEDURES
;*
;*     UPDATES:        
;*
;***************************************************************************
;*         
;*           COPYRIGHT 1983, 1986 INTEL CORPORATION
;*
;*           INTEL CORPORATION PROPRIETARY INFORMATION.  THIS LISTING
;*           IS SUPPLIED UNDER THE TERMS OF A LICENSE  AGREEMENT WITH
;*           INTEL CORPORATION  AND MAY NOT  BE COPIED NOR  DISCLOSED
;*           EXCEPT IN  ACCORDANCE WITH THE  TERMS OF THAT AGREEMENT.
;* 
;***************************************************************************

NAME    DCM44N

USING 0

$nolist
$include(reg44.pdf)
$include(dcm44c.ext)
$include(dcm44c.lit)
$include(r2sys.mac)
$include(dcm44m.a51)
$list

public  non_auto_slave_rcv, non_auto_master_rcv, set_slave_offline
public  serial_timeout, swap_station_states

extrn   bit (s_station_mode, s_timeout_count, s_timeout_set)
extrn   bit (s_init_mode, s_info_mode, s_poll_mode, s_set_rts)

extrn   data (s_queue_ptr, s_poll_queue_in, s_poll_queue_out)
extrn   data (s_last_nsnr, buf_size, req_next_buffer)

extrn   xdata (s_station_state, s_station_poll)

extrn   code (event_detect, serial_gateway_switch, check_receive_buffer)
extrn   code (initiate_order_transmission, auto_send_acknowledge_check)

DCMFW_CODE_SEG          SEGMENT CODE
DCMFW_BIT_SEG           SEGMENT DATA    BITADDRESSABLE
DCMFW_INT_SEG           SEGMENT DATA
DCMFW_EXT_SEG           SEGMENT XDATA
DCMFW_STATION_SEG       SEGMENT XDATA   INPAGE
DCMFW_POLL_SEG          SEGMENT XDATA   INPAGE

RSEG                    DCMFW_CODE_SEG

$eject
;***************************************************************************
;*
;*     ENTRY:          non_auto_slave_rcv
;*
;*     PURPOSE:        Process a frame received by a slave node in non-auto
;*                     mode
;*
;*     ENTERED FROM:   serial_interrupt_check
;*
;*     CALLS:          check_receive_buffer
;*
;*     ENTERS:         auto_send_acknowledge_check, event_detect,
;*                     set_non_auto_transmit
;*
;*     INPUTS:         none
;*
;*     RETURNS:        nothing
;*
;*     DESCRIPTION:    If a sequence error occurred, then go to the
;*                       slave protocol error routine.
;*                     Next, the type of received frame is checked. 
;*                     If it is an information or supervisory frame, then
;*                       either buffer-overflow occurred, or a frame was
;*                       received before the slave was able to get into auto
;*                       mode (after initialization was complete).  In any
;*                       case, go back into auto mode, reenable the receiver,
;*                       and go make an i-frame acknowledge check with the
;*                       rts-flag set, indicating that the rts siu bit needs
;*                       to be set. 
;*                     If it is an unnumbered frame, then if the slave is in
;*                       init mode, then jump to slave_init_generate, else
;*                       jump to slave_protocol_error.
;*
;***************************************************************************

non_auto_slave_rcv:
; A frame was received while the slave was in non-auto mode.  
; First check for type of frame.
;
    jb      ses, slave_protocol_error  ;if protocol error, go process
    jb      ser, slave_protocol_error  ;
    mov     a, rcb                     ;determine frame type
    jnb     acc.i_frame_bpos, slave_info_rcv ;if info frame, jump
    jnb     acc.s_frame_bpos, slave_supv_rcv ;if supervisory frame, jump
    jnb     s_init_mode, slave_protocol_error ;if u-frame, no init mode, jump
    sjmp    slave_init_generate        ;if u-frame, init mode, jump

slave_info_rcv:
slave_supv_rcv:
; An information or supervisory frame was received either before the slave
; was able to go into auto mode, or after the slave was in auto mode but 
; was kicked out of auto mode.  These conditions can be caused by buffer 
; overflow, or receiving the first I-frame before the slave is able to 
; go into auto mode (as the last step in synchronization).
;
    acall   check_receive_buffer       ;check on receive buffer
    setb    am                         ;set slave back into auto mode
    setb    s_set_rts                  ;set rts flag
    setb    rbe                        ;reenable receiver
    ajmp    auto_send_acknowledge_check ;go check for msg. ack.

;---------------------------------------------------------------------------
;  Entry Point:    slave_init_generate
;
;  Purpose:        Determine next control frame for slave to transmit
;                  during synchronization, and transmit the frame.
;
;  Entered From:   non_auto_slave_rcv, protocol_error_reset
;
;  Calls:          check_receive_buffer
;
;  Enters:         set_non_auto_transmit, which enters event_detect
;
;  Inputs:         none
;
;  Returns:        none
;
;  Description:    Checks last transmit control byte against current
;                  received control byte for a slave station. For trans-
;                  mitted anything and received disc, it transmits a ua.
;                  For transmitted ua and received snrm, it transmits a ua,
;                  clears sequence numbers, and later (with transmit ack)
;                  goes into auto mode.  For anything else, it transmits
;                  a frmr.
;---------------------------------------------------------------------------

slave_init_generate:
    setb    s_init_mode                     ;reset flags
    clr     s_info_mode                     ;
    mov     a,rcb                           ;identify the received frame
    cjne    a,#disc_msk,slave_snrm_chk      ;if not disc, jump
    mov     tcb,#ua_msk                     ;else xmit ua in response
    ajmp    set_non_auto_transmit           ;go xmit unnumbered frame

slave_snrm_chk:
    cjne    a,#snrm_msk,slave_other         ;if not snrm, jump
    mov     a,#ua_msk                       ;was a ua xmitted prev to snrm?
    cjne    a,tcb,slave_other               ;if not, xmit frmr
;   mov     tcb,#ua_msk                     ;else transmit ua
    mov     nsnr,#0                         ;initialize ns and nr counts
    clr     s_init_mode                     ;turn off init mode
    mov     sts,#10100000b                  ;tbf=1,rts=1,rest=0
    acall   check_receive_buffer            ;Check for receive buffer
    jnb     si,$                            ;wait for xmit complete interrupt
    mov     sts,#01000010b                  ;rbe=1,am=1,rest=0
    ajmp    event_detect                    ;go wait on event

slave_other:
; if not snrm, then it is either an error (0) or an unrecognized frame.
; generate a frame reject to force resynchronization.
;
    mov     tcb,#frmr_msk                   ;set for transmitting frmr
    ajmp    set_non_auto_transmit           ;go xmit unnumbered frame

;---------------------------------------------------------------------------
;  Entry Point:    slave_protocol_error 
;
;  Purpose:        Handle protocol error conditons on a slave node
;
;  Entered From:   non_auto_slave_rcv 
;
;  Calls:          serial_gateway_switch
;
;  Enters:         slave_init_generate
;
;  Inputs:         none
;
;  Returns:        none
;
;  Description:    This routine processes a non-recoverable error on the  
;                  slave node by returning all message queued for transmission
;                  to the System Buffer Pool, clearing the siu transmit    
;                  registers, and clearing the info mode flag.  It then jumps
;                  to slave_init_generate in order to transmit a disc frame
;                  back to the master.
;---------------------------------------------------------------------------

slave_protocol_error:   
    mov     tbs,#0                          ;clear siu xmit registers
    mov     tbl,#0                          ;
slave_recycle_msgs:                         ;empty all msgs. from queue
    %dequeue_message_def(s_queue_ptr)       ;is there another message?
    jz      slave_recycle_end               ;if not, exit loop
    %req_deallocate                         ;else, deallocate next msg.
    sjmp    slave_recycle_msgs              ;check for another msg.
slave_recycle_end:
    ajmp    slave_init_generate             ;go xmit a snrm to the master

$eject    
;***************************************************************************
;*
;*     ENTRY:          non_auto_master_rcv
;*
;*     PURPOSE:        Process a frame received by a master node.
;*
;*     ENTERED FROM:   serial_interrupt_check
;*
;*     CALLS:          serial_gateway_switch, check_receive_buffer
;*                     enqueue_poll_station_def (macro),
;*                     dequeue_poll_station_def (macro),
;*                     swap_station_states_def  (macro),
;*                     dequeue_message_def      (macro),
;*                     req_deallocate           (macro)
;*
;*     ENTERS:         event_detect, initiate_order_transmission
;*                     
;*
;*     INPUTS:         none
;*
;*     RETURNS:        nothing
;*
;*     DESCRIPTION:    If a sequence error occurred, then go to the
;*                       master protocol error routine.
;*                     Next, the type of received frame is checked. 
;*                     If it is an information frame, then jump to the
;*                       master info receive routine.
;*                     If it is a supervisory frame, then go the the master
;*                       ack check routine to process any acknowledgement.
;*                     If it is an unnumbered frame, then if the master is in
;*                       init mode, then jump to master_init_generate, else
;*                       jump to master_protocol_error.
;*
;***************************************************************************

non_auto_master_rcv: 
    jb      ses, master_protocol_error      ;if protocol error, jump
    jb      ser, master_protocol_error      ;
    mov     a, rcb                          ;determine frame type
    jnb     acc.i_frame_bpos, master_info_rcv ;if info frame, jump
    jnb     acc.s_frame_bpos, master_ack_check ;if supervisory frame, jump
    jnb     s_init_mode, master_protocol_error ;if u-frame, non-init, jump
;   ajmp    master_init_generate            ;if u-frame, init-mode, jump

;---------------------------------------------------------------------------
;  Entry Point:    master_init_generate
;
;  Purpose:        Determine next control frame for master to transmit
;                  during synchronization, and transmit the frame.
;
;  Entered From:   non_auto_master_rcv, protocol_error_reset
;
;  Calls:          none
;
;  Enters:         set_non_auto_transmit, which enters event_detect
;
;  Inputs:         none
;
;  Returns:        none
;
;  Description:    Checks last transmit control byte against current
;                  received control byte for a master station. For trans-
;                  mitted disc and received ua, it generates a snrm.  For
;                  transmitted snrm and received ua, it clears the sequence
;                  numbers and exits init mode.  Any other transmitted control
;                  field transmits a disc.
;---------------------------------------------------------------------------

master_init_generate:
    setb    s_init_mode                     ;reset flags
    clr     s_info_mode                     ;
    clr     s_poll_mode                     ;
    mov     a,rcb                           ;identify the received frame
    cjne    a,#ua_msk,master_disc_xmit      ;if not a ua, go xmit disc
    mov     a,#disc_msk                     ;see if a disc was xmitted
    cjne    a,tcb,master_snrm_chk           ;if not, go check for snrm      
    mov     tcb,#snrm_msk                   ;if disc xmitted before, xmit snrm
    ajmp    set_non_auto_transmit           ;go xmit unnumbered frame

master_disc_xmit:
    mov     tcb,#disc_msk                   ;transmit a disc
    ajmp    set_non_auto_transmit           ;go xmit unnumbered frame

master_snrm_chk:        
    mov     a,#snrm_msk                     ;see if a snrm was xmitted
    cjne    a,tcb,master_disc_xmit          ;if not, go xmit disc
    mov     nsnr,#0                         ;zero the sequence numbers
    clr     s_init_mode                     ;take out of init mode
    ajmp    sps_transmit_rr                 ;and go transmit rr

;---------------------------------------------------------------------------
;  Entry Point:    master_protocol_error
;
;  Purpose:        Handle protocol error conditons
;
;  Entered From:   non_auto_master_rcv