udata_acs
+b res 1 ; byte just read
cslot res 1 ; current slave in slave table, points to flags byte
-main res 1
+cbyte res 1
; one of the following:
; 0000 0000 we're expecting the first byte
;
; MM zz B2 B1 zz zz zz II
;
; main byte from slave
-; X0BB0000
- ; where X is 1 iff we're expecting an `extra byte'
+; M0BB0000
+ ; where M is 1 iff we're expecting an `extra byte'
; otherwise NN is the detection byte we're expecting
sc res 1
sc_extra equ 7 ; we're
slavetable_section udata 0x280
-slavetable res maxpics * 2
- ; each entry is:
- ; 1 byte slave number
- ; 1 byte flags
- ; 00DD0000 where D is 1 iff a detectors board
+
+ste_szln2 equ 3
+ ; each entry is a number of bytes, at these offsets:
+ste_slave equ 0 ; slave number
+ste_flags equ 1 ; flags (stf_...) cslot normally points here
+ste_detbasel equ 2
+ste_lastd0 equ 3
+ste_lastd1 equ 4
+ste_lastd2 equ 5
+ste_detmsgh equ 7
+ste_size equ (1<<ste_szln2)
+slavetable res maxpics * ste_size
+
+stf_detect equ 7
code
;======================================================================
;
; See detect.asm head comment for protocol info, in particular
; the meaning of these bytes.
- mov_wf t ; remember the byte for a moment
- mov_lw slavetable >> 8
- mov_wf FSR1H
- mov_ff cslot, FSR1L
+ ; W = received byte
+ mov_wf b ; W = b = received byte
+
+ mov_lfsr slavetable, 1
+ mov_ff cslot, FSR1L ; FSR1 -> slave's flags
tst_f_ifnz cbyte
bra read_got_notfirst
; this is a first (head) byte:
- and_wfw POSTINC1,
+ bt_f_if0 POSTINC1, stf_detect ; FSR1 -> detbasel
+ bra read_got_first_reversers
+read_got_first_detectors
+ and_lw 0xb0 ; W = M0BB0000
+ mov_wf cbyte ; cbyte = M0BB0000
+ mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
+ rcall read_prep_detectbyte
+ goto addmsgs_dethead
+
+;----------
+read_got_first_reversers
+ bt_f_if1 b, 6
+ bra read_got_bad_first_reversers
+ and_lw 0x80 ; W = M0000000
+ mov_wf cbyte ; cbyte = M0000000
+ mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
+ rcall read_prep_detectbyte
+ goto addmsgs_revhead
+
+;-----
+read_got_bad_first_reversers panic morse_MR
+
+;----------
+read_got_detectors_b1
+ bc_f cbyte, 4 ; cbyte = M0B00000
+ mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
+ inc_f FSR1L ; FSR1 -> lastd1
+ add_lw 8 ; W = detbasel+8
+ rcall read_prep_detectbyte
+ goto addmsgs_all
+
+;----------
+read_got_detectors_b2
+ bc_f cbyte,5 ; cbyte = M0000000
+ mov_fw POSTDEC1 ; W = detbasel; FSR1 -> flags
+ bs_f FSR1L, 2 ; FSR1L -> lastd2
+ add_lw 16 ; W = detbasel+16
+ rcall read_prep_detectbyte
+ goto addmsgs_all
+
+;----------
+read_got_detectbyte_something
+ xor_wfw INDF1 ; lastd<n> = ?d??dddd
+ mov_lw 0x07
+ ior_wff FSR1L ; FSR1L -> detmsgh
+ return ; to addmsgs_<something>
+
+;----------
+read_prep_detectbyte
+; W adjusted detbase l
+; cbyte set for next byte to read
+; b received byte
+; FSR1 -> lastd<n>
+; TOS -> goto addmsgs_<something>
+; NOS return address for i2cmu_read_got_byte
+ mov_wf t ; t = adj.detbasel
+ mov_fw b ; W = ?d??dddd
+ xor_wfw INDF1 ; lastd<n> = ?C??CCCC, Z iff same
+ bra_nz read_got_detectbyte_something
+ xor_wfw INDF1 ; lastd<n> = ?d??dddd
+ ; there's nothing to do
+ pop
+;...
+;----------------------------------------
+i2c_arrange_next_byte
+ tst_f_ifnz cbyte
+ goto i2cm_read_another
+;...
+;----------------------------------------
+i2c_arrange_something
+; figure out what to do next - which pic to address, etc.
+ panic morse_UG
+
+;----------------------------------------
+read_got_notfirst
+ bt_f_if1 cbyte, 4
+ bra read_got_detectors_b1
+ bt_f_if1 cbyte, 5
+ bra read_got_detectors_b2
+ ; it must be an extra byte
+
+ bt_f_if0 b, 7 ; any more ?
+ bc_f cbyte, 7
+ bc_f b, 7
+ call process_got_extra
+ bra i2c_arrange_next_byte
+
+;----------------------------------------
+process_got_extra
+ mov_fw b
+loopback_read_byte
+;...
+; W message
+ xor_lw 0x00 ^ 0x20
+ bra_z cdu_got_pointed
+ xor_lw 0x20 ^ 0xb0
+ bra_z slave_got_aargh
+ panic morse_MX
+
+;========================================
+
+addmsg_testbit macro bit
+ bt_f_if1 w, bit
+ rcall addmsg
+ endm
+
+addmsg_return macro dummy_bit
+ return
+ mov_lw dummy_bit ; makes disassembly a bit clearer than a nop
+ endm
+
+addmsg_ignore macro dummy_bit
+ nop
+ nop
+ endm
+
+addmsg_padding macro dummy_bit
+ nop
+ mov_lw dummy_bit
+ endm
+
+addmsgs_section code 0x2100 + 6*4
+
+addmsgs_dethead addmsg_testbit 6
+ addmsg_ignore 7
+ addmsg_testbit 0
+ addmsg_testbit 1
+ addmsg_testbit 2
+ addmsg_testbit 3
+ addmsg_return 4
+
+addmsgs_all addmsg_testbit 5
+ addmsg_testbit 6
+ addmsg_testbit 7
+ addmsg_testbit 0
+ addmsg_testbit 1
+ addmsg_testbit 2
+ addmsg_testbit 3
+ addmsg_testbit 4
+ addmsg_return 5
+
+ addmsg_padding 6
+ addmsg_padding 7
+
+addmsgs_revhead addmsg_testbit 0
+ addmsg_testbit 1
+ addmsg_testbit 2
+ addmsg_testbit 3
+ addmsg_testbit 4
+ addmsg_testbit 5
+ addmsg_return 6
+
+;----------
+addmsg
+; TOS - 4 -> bt_f_if1 w, <some bit>
+; other conditions set up by read_prep_detectbyte
+; and read_got_detectbyte_something
+; t adj.detbasel
+;
+ rr_fw TOSL ; W = 0???bbb0
+ and_fw 0x0e ; W = 0000bbb0
+ rr_w ; W = 00000bbb
+ set_f FSR0L ; FSR0L = 11111111
+ and_wff FSR0L ; FSR0L = 11111bbb
+ clr_f FSR0H ; FSR0 -> bitnum2bit[b]
+ add_wff t ; t = detect msg low byte
+ mov_fw INDF1 ; W = 1 001 0 SSS
+ mov_wf u ; u = 1 001 0 SSS
+ mov_fw b ; W = ?d??dddd
+stuff here
+ and_wfw INDF0 ; W = .....d..
+
+ xor_wfw
+
+ bt_w_if1 INDF1,
+
+
+
+
+read_got_detectbyte_allsame
+ mov_wf INDF1 ; lastd<n> = ?d??dddd
+
+ pop ; skip return address
+read_done_byte
+
+
+
+ and_lw 0x80 ; W = M0BB0000 / M0000000 ie M0BB0000
+
+ ; this is a first (head) byte from a detectors board:
+
+
+ and_lw 0xb0 ; W = M0BB0000
+
+read_got_
+ mov_fw b
+ xor_wf PREINC1,
+
+ mov_wf b
+
+ mov_
+ and_lw
+
+
+ ; W = b = MdBBdddd /
+ and_wfw INDF1 ; flags, = 10110000 / 10000000
+ mov_wf cbyte ; cbyte = M0BB0000 / M0000000
+
+ bt_f_
+
bt_f_if1 cbyte, 4
~ijackson / trains.git / commitdiff