Send HELLO as a result of all slaves being online. Do not crash if slave is slow...

[trains.git] / detpic / serout.asm

diff --git a/detpic/serout.asm b/detpic/serout.asm
index 33d9b2b6bd5ee21d2b7ee4ea60fcd6e7e7669b0d..16e545fa6074d456d7c7f9cfa757c000f0d6bccf 100644 (file)
--- a/detpic/serout.asm
+++ b/detpic/serout.asm
@@ -1,10 +1,17 @@
 ;======================================================================
 ; SERIAL PORT - TRANSMISSION TO HOST
 
- include common.inc
- code
+  include common.inc
+  code
+
+;======================================================================
+; QUEUEING MESSAGES FOR TRANSMISSION
+
+;----------
+addbyte_toomany panic morse_HB
+
 ;----------------------------------------
-serial_addbyte
+serial_addbyte @
 ;  W                   byte to xmit to host    trashed
 ;  FSR0                        any                     set for serial_addbyte_another
 ;  outbuf, outmsg_*    buffer not full         adjusted appropriately
@@ -13,9 +20,9 @@ serial_addbyte
 ;
        mov_lfsr outbuf, 0
        mov_ff  outmsg_end, FSR0L
-       bs_f    PIR1, TXIE ; ensure we get interrupted and try to xmit
 ;...
-serial_addbyte_another
+;----------------------------------------
+serial_addbyte_another @
 ;  W                   byte to xmit to host    trashed
 ;  FSR0                        from _addbyte[_another] updated for ..._another again
 ;  outbuf, outmsg_*    buffer not full         adjusted appropriately
@@ -26,21 +33,74 @@ serial_addbyte_another
        bc_f    FSR0L, 7
        mov_fw  FSR0L
        mov_wf  outmsg_end
-       cmp_fw_ifne outmsg_begin
+       xor_wfw outmsg_begin
+       bra_z   addbyte_toomany
+       ; no, we're ok:
+
+       bt_f_if1 PIE1, TXIE
+       return ; don't bother messing about if tx is already enabled
+
+; we fall through to portb_read to reenable TXIE if appropriate
+;...
+;======================================================================
+; FLOW CONTROL BY HOST OF OUR TRANSMISSIONS
+
+;...
+;----------------------------------------
+portb_read @
+;
+;  W                   undefined       value from PORTB
+;  TXIE                        any             enabled iff host allows us to xmit
+;
+; Note that this will reenable TXIE even if the serial buffer is empty,
+; every time portb_read is called.  This doesn't matter very much
+; because the serialtx_intrl routine will disable it again straight
+; away.
+;
+       mov_fw  PORTB
+       bc_f    INTCON, RBIF
+
+       bt_w_if1  p0_rs232_fcin >> 4
+       bra     txfc_disable
+       ; tx enable:
+
+       call    led_green ; we're transmitting
+       bs_f    PIE1, TXIE
        return
-       ; too many
-       panic morse_HB
+
+;----------
+txfc_disable
+       bc_f    PIE1, TXIE
+       goto    led_red ; flow control forces us not to transmit
 
 ;----------------------------------------------------------------------
-serialtx_intrl
-       bt_f_if1 INTCON, RBIF
+serialtxfc_intrl @
+       bt_f_if0 INTCON, RBIF
+       return
+       ; yes, it's us:
+
        rcall   portb_read ; check flow control
+       intrl_handled_nostack
+
+;----------------------------------------------------------------------
+serialtxfc_init @
+       bc_f    INTCON2, RBIP
+       bs_f    INTCON, RBIE
+       rcall   portb_read
+       pin_l   p0_rs232_fcout ; set outgoing RTS/CTS active
+       return
 
+;======================================================================
+; ACTUAL TRANSMISSION
+
+;----------------------------------------------------------------------
+serialtx_intrl @
        ; are we ready to transmit ?
        bt_f_if0 PIR1, TXIF
        return
-       bt_f_if0 PIR1, TXIE
+       bt_f_if0 PIE1, TXIE
        return
+       ; yes, it's us:
 
        mov_lfsr outbuf, 0
        mov_fw  outmsg_begin
@@ -58,59 +118,37 @@ serialtx_intrl
 tx_justsent_noacknmra
        inc_f   outmsg_begin
        bc_f    outmsg_begin, outbuf_szln2
-       call    led_green ; we're transmitting
-       goto    i2c_consider_restartread
-
-tx_bufempty
-       ; maybe we send an NMRADONE
-       mov_fw  acknmra
-       bra_nz  tx_acknmra_send
-       ; nothing at all to do:
-       bc_f    PIR1, TXIE
-       goto    led_black ; we're not transmitting
+       call    i2c_consider_restartread
+tx_alliswell
+       intrl_handled_nostack
 
+;----------
 tx_acknmra_insert
        sub_wff acknmra ; we're acking these now
        mov_wf  INDF0 ; write it over the message we just sent
-       goto    led_green
+       bra     tx_alliswell
 
+;----------
 tx_acknmra_send
        sub_wff acknmra ; we're acking these now
        mov_wf  TXREG
-       goto    led_green
-
-;----------------------------------------
-portb_read
-;  W                   undefined       value from PORTB
-       mov_fw  PORTB
-       bc_f    INTCON, RBIF
-
-       bt_w_if0  p0_rs232_fcin >> 4
-       bra     tx_fcdisable
-       ; tx enable:
+       bra     tx_alliswell
 
-       bs_f    PIR1, TXIE
-       bc_f    INTCON, RBIE
-       return
-
-tx_fcdisable
-       bc_f    PIR1, TXIE
-       bs_f    INTCON, RBIE
-       goto    led_red ; flow control forces us not to transmit
-
-;----------------------------------------------------------------------
-serialtxfc_init
-       bs_f    INTCON, RBIE
-       bc_f    INTCON2, RBIP
-       rcall   porb_read
-       return
+;----------
+tx_bufempty
+       ; maybe we send an NMRADONE
+       mov_fw  acknmra
+       bra_nz  tx_acknmra_send
+       ; nothing at all to do:
+       bc_f    PIE1, TXIE
+       call    led_black ; we're not transmitting
+       intrl_handled_nostack
 
 ;----------------------------------------------------------------------
-serialtxbuf_init
+serialtxbuf_init @
        clr_f   outmsg_end
        clr_f   outmsg_begin
-       mov_lw  b'00001001'
-       goto    serial_addbyte
+       return
 
 ;======================================================================
- include final.inc
+  include final.inc