1 ;======================================================================
2 ; MASTER - SCANNING ETC.
6 ;----------------------------------------------------------------------
9 ; for reading and detection:
10 b res 1 ; byte just read
11 cslot res 1 ; current slave in slave table, points to flags byte
13 ; one of the following:
14 ; 0000 0000 we're expecting the first byte
15 ; M0B1 0000 we're expecting more detection byte 1
16 ; M010 0000 we're expecting more detection byte 2
17 ; 1000 0000 we're expecting an extra byte
18 ; ???? ???1 reading halted for any reason:
19 cbyte_halted equ 0 ; also set briefly while we decide what to do next
21 wslave res 1 ; slave we need to write to
22 outmsg_targetlen res 1 ;
24 ;======================================================================
25 ; HANDLING OF I2C EVENTS
27 near_getwritebyteyes code
28 ;----------------------------------------
29 i2c_getwritebyte_yes @
30 pop ; we don't care where we were in i2cmu_write_next_byte
31 bc_f STATUS, Z ; yes, we want to write this byte
32 return ; from i2cmu_write_next_byte
35 ;----------------------------------------
38 ; add calls to getwritebyte_<foo> here:
39 call polarity_getwritebyte
40 call points_getwritebyte
41 ; end of list of calls to getwritebyte_<foo>
42 ; so, no-one wants this slave:
46 ;----------------------------------------
48 ; handles i2c interrupt using i2cm_interrupt[_definite],
49 ; according to the rules for <something>_intrl.
53 call i2cm_interrupt_definite
56 ;======================================================================
57 ; PROCESSING OF INCOMING BYTES - CORE AND DETECTION
59 ;----------------------------------------
62 ; State Reading Reading-Wait
65 ; See detect.asm head comment for protocol info, in particular
66 ; the meaning of these bytes.
68 mov_wf b ; W = b = received byte
73 Df b ; also restores b to W
75 mov_lfsr slavetable, 1
76 mov_ff cslot, FSR1L ; FSR1 -> slave's flags
80 ; this is a first (head) byte:
82 bt_f_if0 POSTINC1, stf_detect ; FSR1 -> detbasel
83 bra read_got_first_reversers
84 read_got_first_detectors ; b = MdBBdddd
85 and_lw 0xb0 ; W = M0BB0000
86 mov_wf cbyte ; cbyte = M0BB0000
87 mov_lw 0x4f ; W = 01001111
88 and_wff b ; b = 0d00dddd
89 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
90 rcall read_got_detectbyte_prep ; b = 0d00dddd
92 bt_f_if1 b, 6 ; b bit .d......
93 bs_f b, 4 ; b = 0d0ddddd
94 ; ^ ^ copies of same bit
95 ; u = (still) 0C00CCCC
96 ; or, using detection segment bit numbers:
102 read_got_first_reversers
104 bra read_got_bad_first_reversers
105 and_lw 0x80 ; W = M0000000
106 mov_wf cbyte ; cbyte = M0000000
107 bc_f b, 7 ; b = 00dddddd
108 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
109 rcall read_got_detectbyte_prep
113 read_got_bad_first_reversers panic morse_MR
116 read_got_detectors_b1 ; b = dddddddd
117 ; ; W = detbasel; FSR1 -> detbasel
118 add_lw 5 ; W = adjdetbasel
119 bs_f FSR1L, 2 ; FSR1L -> lastd1
120 bc_f cbyte, 4 ; cbyte = M0B00000
121 rcall read_got_detectbyte_prep
125 read_got_detectors_b2 ; b = dddddddd
126 ; ; W = detbasel; FSR1 -> detbasel
127 add_lw 13 ; W = adjdetbasel
128 inc_f FSR1L ; FSR1 -> lastd0
129 inc_f FSR1L ; FSR1 -> lastd2
130 bc_f cbyte,5 ; cbyte = M0000000
131 rcall read_got_detectbyte_prep
135 read_got_detectbyte_prep_ifsomething
137 ; This is a branch of read_got_detectbyte_prep, called if we're doing
138 ; `return' rather than `pop+return'. For conditions on return, see
139 ; read_got_detectbyte_prep; these are supposed to be (basically) the
140 ; same as the entry conditions for addmsgs_<kind>.
154 Df u ; also restores u to W
156 xor_wff INDF1 ; lastd<n> = [d0]*
157 ; to force test of repeated detection notification,
158 ; comment out previous line
160 ior_wff FSR1L ; FSR1L -> detmsgh
161 return ; to addmsgs_<something>, very shortly
163 ;----------------------------------------
166 mov_fw PREINC1 ; W = detbasel; FSR1 -> detbasel
168 bra read_got_detectors_b1
170 bra read_got_detectors_b2
171 ; it must be an extra byte
173 bt_f_if0 b, 7 ; any more ?
176 call process_got_extra
177 bra i2c_arrange_next_byte
180 read_got_detectbyte_prep
182 ; Sees if anything has changed. If no changes pops one return address
183 ; and branches to i2c_arrange_next_byte; if some changes, returns to
186 ; So, caller should be i2cmu_read_got_byte, and next stuff
187 ; should basically be a call to addmsg_<something> (perhaps preceded
188 ; by a bit of fiddling of b). addmsg_<something> will finish
189 ; by branching to i2c_arrange_next_byte.
191 ; call return pop+return
192 ; W adjdetbasel preserved undefined
193 ; b [d0]* preserved preserved
194 ; FSR1 -> lastd<n> detmsgh preserved
195 ; cbyte set for next read etc. preserved preserved
196 ; u undefined [C0]* preserved
197 ; lastd<n> [o0]* [d0]* preserved = [d0]*
199 ; TOS -> (optionally, fiddle b, and then:) goto addmsgs_<something>
200 ; NOS return address for i2cmu_read_got_byte
202 mov_wf t ; t = adjdetbasel
207 xor_wfw INDF1 ; W = [C0]*, Z iff same
208 ; where C set iff change to that detection segment
209 bra_nz read_got_detectbyte_prep_ifsomething
210 ; there's nothing to do
213 ;----------------------------------------
214 i2c_arrange_next_byte
216 goto i2cm_read_another
218 ;======================================================================
219 ; DECIDING WHICH SLAVE TO ADDRESS
221 i2c_arrange_something
223 ; figure out what to do next - which pic to address, etc.
224 bs_f cbyte, cbyte_halted
226 tst_f_ifnz wslave ; anyone asked to write ?
229 ; Anyone else to write to ?
230 ; add calls to needwrite_<foo> here:
231 call polarity_needwrite
232 call points_needwrite
233 ; end of list of calls to needwrite_<foo>
235 ; no, if we're here, no-one wants to write:
238 ; no writing needed, we consider reading:
239 bt_f_if1 flags, flags_polarising
240 return ; do not scan while booster PWM is off while polarising
241 ; to avoid all trains disappearing and reappearing
245 and_lw outbuf_size - 1
246 cmp_fw_ifle outmsg_targetlen
247 return ; target len < actual len, do not add anything
248 ; ok, there's space, go ahead:
249 bc_f cbyte, cbyte_halted
252 add_wff cslot ; cslot -> next ste_flags
253 mov_lfsr slavetable, 1 ; FSR1H -> slavetable
254 mov_ff cslot, FSR1L ; FSR1 -> new ste_flags
256 bt_f_if1 POSTDEC1, stf_sentinel ; FSR1 -> ste_slave
257 bra nextslave_looparound
258 ; Ok, we have a slave:
261 mov_fw INDF1 ; W = new slave number
265 ; now we do our own detection
266 mov_lw (slavetable + ste_flags) & 0xff ; select our own slot
269 call read_detection_head_master
270 goto i2cmu_read_got_byte
272 ;----------------------------------------
274 ; Informs mascan that we need to write to some slave.
275 ; Some time after this, mascan will call getwritebyte_<everything>
276 ; and this must yield at least one byte to write.
277 ; W slave that we must write to
279 bt_f_if0 cbyte, cbyte_halted
280 return ; we're currently doing something
284 ; wslave slave to write to
285 bc_f cbyte, cbyte_halted
289 goto i2cm_write_start
291 ;----------------------------------------
292 i2c_consider_restartread @
293 bt_f_if0 cbyte, cbyte_halted
295 bra nextslave_nowrite
297 ;======================================================================
301 mov_lw (slavetable + ste_flags) & 0xff
302 ; pretend we've just done us, to start with 1st actual slave
305 bs_f cbyte, cbyte_halted ; serial output of `hello' will start us up
309 mov_lfsr slavetable, 0 ; FSR0 -> slavetable
310 load_tblptr pic2detinfo ; TBLPTR* -> pic2detinfo
311 clr_f t ; t = loop counter
313 tblrd_postinc_fixup ; TABLAT = EOOOOSSS
314 mov_fw TABLAT ; W = EOOOOSSS, N = E
316 tblrd_postinc_fixup ; TABLAT = DSSSSSSS, N (still) = E
317 bra_nn mascan_init_ifabsent ; E.......
319 mov_ff t, POSTINC0 ; ste_slave = slave
320 mov_wf u ; u = 1OOOOSSS
322 bra_nz mascan_bad_detinfo0
325 mov_fw TABLAT ; W = DSSSSSSS
326 and_lw 0x80 ; W = D0000000
327 mov_wf POSTINC0 ; ste_flags = D0000000
329 mov_fw TABLAT ; W = DSSSSSSS
330 bc_w 7 ; W = 0SSSSSSS = first
331 add_lw -0xf8 ; W = first - 0xf8 = detbasel
332 mov_wf POSTINC0 ; detbasel
334 clr_f POSTINC0 ; lastd0
335 clr_f POSTINC0 ; lastd2
336 set_f POSTINC0 ; unused
337 clr_f POSTINC0 ; lastd1
339 mov_fw u ; W = 10000SSS
340 xor_lw b'10011000' ^ 0x80 ; W = detmsgh
341 mov_wf POSTINC0 ; detmsgh
345 bt_f_if0 t, maxpics_ln2
347 ; we've read the whole flash table
349 if slavetable == 0x400
351 bra mascan_bad_toomany
354 clr_f POSTINC0 ; ste_slave
355 mov_lw (1<<stf_detect)|(1<<stf_sentinel)
356 mov_wf POSTINC0 ; ste_flags
357 ; rest of final entry, and rest of table, is undefined
359 ; at 9600, it's about 1ms per char.
360 ; we allow 1ms to scan 2 pics via i2c.
361 ; so our target len is (no of pics)/2
362 ; plus 2 bytes of slop
365 mov_wf outmsg_targetlen
369 mascan_bad_detinfo0 panic morse_DF
370 mascan_bad_toomany panic morse_DG
372 ;======================================================================
373 ; PROCESSING OF INCOMING BYTES - EXTRA (NON-DETECTION)
376 ;----------------------------------------
388 ;======================================================================
389 ; GENERATION OF DETECTION MESSAGES FOR HOST - MAD BT_F_IF1 TABLES
391 addmsg_testbit macro addmsg_macro_bit
392 bt_f_if1 u, addmsg_macro_bit
396 addmsg_return macro dummy_addmsg_macro_bit
397 goto i2c_arrange_next_byte
400 addmsg_ignore macro dummy_addmsg_macro_bit
405 addmsg_padding macro dummy_addmsg_macro_bit
407 mov_lw dummy_addmsg_macro_bit
410 ;----------------------------------------
413 ; on entry after first addmsg_one, or when done
414 ; W, STATUS, v, FSR0 undefined trashed
415 ; t adjdetbasel not modified by addmsgs_<kind> or _one
416 ; u [C0]* not modified by addmsgs_<kind> or _one
417 ; b [d0]* not modified by addmsgs_<kind> or _one
418 ; lastd<n> [d0]* (new) not modified by addmsgs_<kind> or _one
419 ; FSR1 -> detmsgh not modified by addmsgs_<kind> or _one
420 ; outbuf, outmsg_* not full, updated appropriately
421 ; all others any not interfered with
423 ; (this is all set up by read_prep_detectbyte and
424 ; read_got_detectbyte_prep_ifsomething)
425 ; when done, branches to i2c_arrange_next_byte, rather than returning
427 addmsgs_section code ( 7 )*4 + 0x2100
430 ; |- PCL bbb value after macro - number in this
431 ; V column should increment 1 each line
433 addmsgs_revhead addmsg_testbit 0
441 addmsgs_all addmsg_testbit 7
451 addmsgs_dethead addmsg_testbit 0
455 addmsg_testbit 6 ; bit 6 was copied to 4 but only in b, not u
460 ; TOS - 4 -> bt_f_if1 u, b'bbb'
462 ; other conditions on entry and exit as for entry to addmsgs_<kind>, above
465 rr_fw TOSL ; W = 0???bbb0
467 ior_lw 0xf8 ; W = 11111bbb
468 mov_wf FSR0L ; FSR0L = 11111bbb
469 clr_f FSR0H ; FSR0 -> bitnum2bit[bbb]
470 add_wfw t ; W = adjdetbasel + 11111bbb
471 ; ie = 0 SSSSSSS (det msg low byte)
472 mov_wf v ; v = 0 SSSSSSS (det msg low byte)
476 and_wfw INDF0 ; train: W = 0x00, Z=1; none: W = 0*d0*, Z=0
478 mov_lw 0x08 ; train: W = 0 000 0 000; none: W = 0 000 1 000
479 xor_wfw INDF1 ; W = 1 001 Y SSS (det msg high byte)
483 mov_fw v ; W = 0 SSSSSSS (det msg low byte)
485 goto serial_addbyte_another
487 addmsg_bad panic morse_DJ
489 ;======================================================================