; 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_detbasel equ 2 ; added to 11111bbb to make 0SSSSSSS; ie first-0xf8
+ste_lastd0 equ 3 ; } [o0]* ie every bit is either 0 (for an
+ste_lastd1 equ 4 ; } irrelevant bit) or o, meaning the
+ste_lastd2 equ 5 ; } previously seen detection data bit
+ste_detmsgh equ 7 ; 1 001 1 000 being 1 001 Y SSS
ste_size equ (1<<ste_szln2)
slavetable res maxpics * ste_size
bt_f_if0 POSTINC1, stf_detect ; FSR1 -> detbasel
bra read_got_first_reversers
-read_got_first_detectors
+read_got_first_detectors ; b = MdBBdddd
and_lw 0xb0 ; W = M0BB0000
mov_wf cbyte ; cbyte = M0BB0000
+ mov_lw 0x4f ; W = 01001111
+ and_wff b ; b = 0d00dddd
mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
- rcall read_prep_detectbyte
+ rcall read_prep_detectbyte ; b = 0d00dddd
+ ; u = 0C00CCCC
+ bt_f_if1 b, 6 ; b bit .d......
+ bs_f b, 4 ; b = 0d0ddddd
+ ; ^ ^ copies of same bit
+ ; u = (still) 0C00CCCC
+ ; or, using detection segment bit numbers:
+ ; b = z4z43210
+ ; u = z4zz3210
goto addmsgs_dethead
;----------
bra read_got_bad_first_reversers
and_lw 0x80 ; W = M0000000
mov_wf cbyte ; cbyte = M0000000
+ bc_f b, 7 ; b = 00dddddd
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
+read_got_detectors_b1 ; b = dddddddd
bc_f cbyte, 4 ; cbyte = M0B00000
mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
inc_f FSR1L ; FSR1 -> lastd1
- add_lw 8 ; W = detbasel+8
+ add_lw 5 ; W = detbasel+8
rcall read_prep_detectbyte
goto addmsgs_all
;----------
-read_got_detectors_b2
+read_got_detectors_b2 ; b = dddddddd
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
+ add_lw 13 ; W = detbasel+16
rcall read_prep_detectbyte
goto addmsgs_all
;----------
-read_got_detectbyte_something
-; branched from read_prep_detectbyte
-; b -> ?d??ddddd
-; W ?C??CCCC
-; t adj.detbasel
+read_got_detectbyte_prep_ifsomething
+;
+; This is a branch of read_got_detectbyte_prep, called if we're doing
+; `return' rather than `pop+return'. For conditions on return, see
+; read_got_detectbyte_prep; these are supposed to be (basically) the
+; same as the entry conditions for addmsgs_<kind>.
+;
+; on entry
+; W [C0]*
+; t adjdetbasel
+; u undefined
+; b [d0]*
+; lastd<n> [o0]*
; FSR1 -> lastd<n>
- fixme need to preserve CCC's for use by addmsg_<something>
- xor_wfw INDF1 ; lastd<n> = ?d??dddd
+;
+ mov_wf u ; u = [C0]*
+ xor_wfw INDF1 ; lastd<n> = [d0]*
mov_lw 0x07
ior_wff FSR1L ; FSR1L -> detmsgh
- return ; to addmsgs_<something>
+ return ; to addmsgs_<something>, very shortly
;----------------------------------------
read_got_notfirst
panic morse_MX
;----------
-read_prep_detectbyte
-; W adjusted detbase l
-; cbyte set for next byte to read
-; b received byte
-; FSR1 -> lastd<n>
-; TOS -> goto addmsgs_<something>
+read_got_detectbyte_prep
+;
+; Sees if anything has changed. If no changes pops one return address
+; and branches to i2c_arrange_next_byte; if some changes, returns to
+; calling point.
+;
+; So, caller should be i2cmu_read_got_byte, and next stuff
+; should basically be a call to addmsg_<something> (perhaps preceded
+; by a bit of fiddling of b). addmsg_<something> will finish
+; by branching to i2c_arrange_next_byte.
+;
+; call return pop+return
+; W adjdetbasel preserved undefined
+; b [d0]* preserved preserved
+; FSR1 -> lastd<n> detmsgh preserved
+; cbyte set for next read etc. preserved preserved
+; u undefined [C0]* preserved
+; lastd<n> [o0]* [d0]* preserved = [d0]*
+;
+; TOS -> (optionally, fiddle b, and then:) 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 ; W = ?C??CCCC, Z iff same
+;
+ mov_wf t ; t = adjdetbasel
+ mov_fw b ; W = [d0]*
+ xor_wfw INDF1 ; W = [C0]*, Z iff same
; where C set iff change to that detection segment
- bra_nz read_got_detectbyte_something
- xor_wfw INDF1 ; lastd<n> = ?d??dddd
+ bra_nz read_got_detectbyte_prep_ifsomething
; there's nothing to do
pop
;...
; GENERATION OF DETECTION MESSAGES FOR HOST - MAD BT_F_IF1 TABLES
addmsg_testbit macro bit
- bt_f_if1 w, bit fixme need to test something other than w !
- rcall addmsg
+ bt_f_if1 u, bit fixme need to test something other than w !
+ rcall addmsg_one
endm
addmsg_return macro dummy_bit
- return
- mov_lw dummy_bit ; makes disassembly a bit clearer than a nop
+ goto i2c_arrange_next_byte
endm
addmsg_ignore macro dummy_bit
mov_lw dummy_bit
endm
-fixme comment this better
-addmsg registers on entry
-strangeness with offsets etc.
-
-addmsgs_section code 0x2100 + 6*4
+;----------------------------------------
+;addmsgs_<kind>
+;
+; on entry after first addmsg_one, or when done
+; W, STATUS, v, FSR0 undefined trashed
+; t adjdetbasel not modified by addmsgs_<kind> or _one
+; u [C0]* not modified by addmsgs_<kind> or _one
+; b [d0]* not modified by addmsgs_<kind> or _one
+; lastd<n> [d0]* (new) not modified by addmsgs_<kind> or _one
+; FSR1 -> detmsgh not modified by addmsgs_<kind> or _one
+; outbuf, outmsg_* not full, updated appropriately
+; all others any not interfered with
+;
+; (this is all set up by read_prep_detectbyte and
+; read_got_detectbyte_prep_ifsomething)
+; when done, branches to i2c_arrange_next_byte, rather than returning
-addmsgs_dethead addmsg_testbit 6
- addmsg_ignore 7
- addmsg_testbit 0
+addmsgs_section code ( 7 )*4 + 0x2100
+;
+; A
+; |- PCL bbb value after macro - number in this
+; V column should increment 1 each line
+;
+addmsgs_revhead addmsg_testbit 0
addmsg_testbit 1
addmsg_testbit 2
addmsg_testbit 3
- addmsg_return 4
+ addmsg_testbit 4
+ addmsg_testbit 5
+ addmsg_return 6
-addmsgs_all addmsg_testbit 5
- addmsg_testbit 6
- addmsg_testbit 7
+addmsgs_all 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
+ addmsg_testbit 5
+ addmsg_testbit 6
+ addmsg_return 7
-addmsgs_revhead addmsg_testbit 0
+addmsgs_dethead addmsg_testbit 0
addmsg_testbit 1
addmsg_testbit 2
addmsg_testbit 3
- addmsg_testbit 4
- addmsg_testbit 5
- addmsg_return 6
+ addmsg_testbit 6 ; bit 6 was copied to 4 but only in b, not u
+ addmsg_return 5
;----------
-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
-;
+addmsg_one
+; TOS - 4 -> bt_f_if1 w, b'bbb'
+; TOSL ???bbb00
+; other conditions on entry and exit as for entry to addmsgs_<kind>, above
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
- and_wfw INDF0 ; W = .....d.., Z iff detect
- bt_f_if1 STATUS, Z
- bs_f u, 3 ; u = 1 001 Y SSS
- mov_fw u
- rcall serial_addbyte
- mov_fw t
+ rr_w ; W = 00???bbb
+ ior_fw 0xf8 ; W = 11111bbb
+ mov_wf FSR0L ; FSR0L = 11111bbb
+ clr_f FSR0H ; FSR0 -> bitnum2bit[bbb]
+ add_wfw t ; W = adjdetbasel + 11111bbb
+ ; ie = 0 SSSSSSS (det msg low byte)
+ mov_wf v ; v = 0 SSSSSSS (det msg low byte)
+
+ mov_fw b ; W = [d0]*
+ and_wfw INDF0 ; train: W = 0x00, Z=1; none: W = 0*d0*, Z=0
+ bt_f_if0 STATUS, Z
+ mov_lw 0x08 ; train: W = 0 000 0 000; none: W = 0 000 1 000
+ xor_wfw INDF1 ; W = 1 001 Y SSS (det msg high byte)
+ call serial_addbyte
+
+ mov_fw v ; W = 0 SSSSSSS (det msg low byte)
goto serial_addbyte_another
;======================================================================
~ijackson / trains.git / commitdiff