fix totally broken serial FC and RBIF handling

diff --git a/detpic/program.asm b/detpic/program.asm
index 58475065f4dd0c31faf91fd06778b8b37b957562..1edd9d596718fb27f34c7a9197e0dbd037b08e56 100644 (file)
--- a/detpic/program.asm
+++ b/detpic/program.asm
@@ -91,6 +91,7 @@ master_interrupt_low
        call    tick_intrl
        call    nmra_serialrx_intrl
        call    power_fault_intrl
+       call    serialtxfc_intrl
        call    serialtx_intrl
        call    points_local_intrl
        call    i2cm_intrl

diff --git a/detpic/serout.asm b/detpic/serout.asm
index 96718610e3d8019256bbb7ff8ae622e07c3ccebf..e0835c4b868d353dced83c071c2530eda429319a 100644 (file)
--- a/detpic/serout.asm
+++ b/detpic/serout.asm
@@ -3,6 +3,13 @@
 
   include common.inc
   code
+
+;======================================================================
+; QUEUEING MESSAGES FOR TRANSMISSION
+
+;----------
+addbyte_toomany panic morse_HB
+
 ;----------------------------------------
 serial_addbyte
 ;  W                   byte to xmit to host    trashed
@@ -13,8 +20,8 @@ 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
 ;  W                   byte to xmit to host    trashed
 ;  FSR0                        from _addbyte[_another] updated for ..._another again
@@ -26,21 +33,73 @@ 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 INTCON, 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_if0  p0_rs232_fcin >> 4
+       bra     txfc_disable
+       ; tx enable:
+
+       bs_f    PIR1, TXIE
        return
-       ; too many
-       panic morse_HB
+
+;----------
+txfc_disable
+       bc_f    PIR1, 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
        return
+       ; yes, it's us:
 
        mov_lfsr outbuf, 0
        mov_fw  outmsg_begin
@@ -58,53 +117,32 @@ serialtx_intrl
 tx_justsent_noacknmra
        inc_f   outmsg_begin
        bc_f    outmsg_begin, outbuf_szln2
+       call    i2c_consider_restartread
+tx_alliswell
        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
+       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
+;----------
+tx_bufempty
+       ; maybe we send an NMRADONE
+       mov_fw  acknmra
+       bra_nz  tx_acknmra_send
+       ; nothing at all to do:
        bc_f    PIR1, TXIE
-       bs_f    INTCON, RBIE
-       goto    led_red ; flow control forces us not to transmit
-
-;----------------------------------------------------------------------
-serialtxfc_init
-       bc_f    INTCON2, RBIP
-       bs_f    INTCON, RBIE
-       rcall   portb_read
-       pin_l   p0_rs232_fcout ; set outgoing RTS/CTS active
-       return
+       call    led_black ; we're not transmitting
+       intrl_handled_nostack
 
 ;----------------------------------------------------------------------
 serialtxbuf_init

diff --git a/detpic/serout.fin b/detpic/serout.fin
index b379166515657b72c70a7e396321b4804029accf..f3a3546e6cdba1add9bd9c5ad468f0c373060816 100644 (file)
--- a/detpic/serout.fin
+++ b/detpic/serout.fin
@@ -1,6 +1,7 @@
   extern serial_addbyte
   extern serial_addbyte_another
   extern serialtx_intrl
+  extern serialtxfc_intrl
   extern serialtxfc_init
   extern serialtxbuf_init
   extern portb_read