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 due to lack of buffer space:
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 ;----------------------------------------
37 ; add calls to getwritebyte_<foo> here:
38 call polarity_getwritebyte
39 call points_getwritebyte
40 ; end of list of calls to getwritebyte_<foo>
41 ; so, no-one wants this slave:
45 ;----------------------------------------
47 ; handles i2c interrupt using i2cm_interrupt[_definite],
48 ; according to the rules for <something>_intrl.
51 call i2cm_interrupt_definite
54 ;======================================================================
55 ; PROCESSING OF INCOMING BYTES - CORE AND DETECTION
57 ;----------------------------------------
60 ; State Reading Reading-Wait
63 ; See detect.asm head comment for protocol info, in particular
64 ; the meaning of these bytes.
66 mov_wf b ; W = b = received byte
69 mov_lfsr slavetable, 1
70 mov_ff cslot, FSR1L ; FSR1 -> slave's flags
74 ; this is a first (head) byte:
76 bt_f_if0 POSTINC1, stf_detect ; FSR1 -> detbasel
77 bra read_got_first_reversers
78 read_got_first_detectors ; b = MdBBdddd
79 and_lw 0xb0 ; W = M0BB0000
80 mov_wf cbyte ; cbyte = M0BB0000
81 mov_lw 0x4f ; W = 01001111
82 and_wff b ; b = 0d00dddd
83 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
84 rcall read_got_detectbyte_prep ; b = 0d00dddd
86 bt_f_if1 b, 6 ; b bit .d......
87 bs_f b, 4 ; b = 0d0ddddd
88 ; ^ ^ copies of same bit
89 ; u = (still) 0C00CCCC
90 ; or, using detection segment bit numbers:
96 read_got_first_reversers
98 bra read_got_bad_first_reversers
99 and_lw 0x80 ; W = M0000000
100 mov_wf cbyte ; cbyte = M0000000
101 bc_f b, 7 ; b = 00dddddd
102 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
103 rcall read_got_detectbyte_prep
107 read_got_bad_first_reversers panic morse_MR
110 read_got_detectors_b1 ; b = dddddddd
111 bc_f cbyte, 4 ; cbyte = M0B00000
112 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
113 inc_f FSR1L ; FSR1 -> lastd1
114 add_lw 5 ; W = detbasel+8
115 rcall read_got_detectbyte_prep
119 read_got_detectors_b2 ; b = dddddddd
120 bc_f cbyte,5 ; cbyte = M0000000
121 mov_fw POSTDEC1 ; W = detbasel; FSR1 -> flags
122 bs_f FSR1L, 2 ; FSR1L -> lastd2
123 add_lw 13 ; W = detbasel+16
124 rcall read_got_detectbyte_prep
128 read_got_detectbyte_prep_ifsomething
130 ; This is a branch of read_got_detectbyte_prep, called if we're doing
131 ; `return' rather than `pop+return'. For conditions on return, see
132 ; read_got_detectbyte_prep; these are supposed to be (basically) the
133 ; same as the entry conditions for addmsgs_<kind>.
144 xor_wfw INDF1 ; lastd<n> = [d0]*
146 ior_wff FSR1L ; FSR1L -> detmsgh
147 return ; to addmsgs_<something>, very shortly
149 ;----------------------------------------
152 bra read_got_detectors_b1
154 bra read_got_detectors_b2
155 ; it must be an extra byte
157 bt_f_if0 b, 7 ; any more ?
160 call process_got_extra
161 bra i2c_arrange_next_byte
164 read_got_detectbyte_prep
166 ; Sees if anything has changed. If no changes pops one return address
167 ; and branches to i2c_arrange_next_byte; if some changes, returns to
170 ; So, caller should be i2cmu_read_got_byte, and next stuff
171 ; should basically be a call to addmsg_<something> (perhaps preceded
172 ; by a bit of fiddling of b). addmsg_<something> will finish
173 ; by branching to i2c_arrange_next_byte.
175 ; call return pop+return
176 ; W adjdetbasel preserved undefined
177 ; b [d0]* preserved preserved
178 ; FSR1 -> lastd<n> detmsgh preserved
179 ; cbyte set for next read etc. preserved preserved
180 ; u undefined [C0]* preserved
181 ; lastd<n> [o0]* [d0]* preserved = [d0]*
183 ; TOS -> (optionally, fiddle b, and then:) goto addmsgs_<something>
184 ; NOS return address for i2cmu_read_got_byte
186 mov_wf t ; t = adjdetbasel
188 xor_wfw INDF1 ; W = [C0]*, Z iff same
189 ; where C set iff change to that detection segment
190 bra_nz read_got_detectbyte_prep_ifsomething
191 ; there's nothing to do
194 ;----------------------------------------
195 i2c_arrange_next_byte
197 goto i2cm_read_another
199 ;======================================================================
200 ; DECIDING WHICH SLAVE TO ADDRESS
202 i2c_arrange_something
204 ; figure out what to do next - which pic to address, etc.
205 bs_f cbyte, cbyte_halted
207 tst_f_ifnz wslave ; anyone asked to write ?
210 ; Anyone else to write to ?
211 ; add calls to needwrite_<foo> here:
212 call polarity_needwrite
213 call points_needwrite
214 ; end of list of calls to needwrite_<foo>
216 ; no, if we're here, no-one wants to write:
219 ; no writing needed, we consider reading:
220 bt_f_if1 flags, flags_polarising
221 return ; do not scan while booster PWM is off while polarising
222 ; to avoid all trains disappearing and reappearing
226 and_lw outbuf_size - 1
227 cmp_fw_ifle outmsg_targetlen
228 return ; target len < actual len, do not add anything
229 ; ok, there's space, go ahead:
230 bc_f cbyte, cbyte_halted
233 add_wff cslot ; cslot -> next ste_flags
234 mov_lfsr slavetable, 1 ; FSR1H -> slavetable
235 mov_ff cslot, FSR1L ; FSR1 -> new ste_flags
238 bt_f_if1 POSTDEC1, stf_sentinel ; FSR1 -> ste_slave
239 bra nextslave_looparound
240 ; Ok, we have a slave:
242 mov_fw INDF1 ; W = new slave number
246 ; now we do our own detection
247 mov_lw (slavetable + ste_flags) & 0xff ; select our own slot
249 call read_detection_head_master
250 goto i2cmu_read_got_byte
253 ;----------------------------------------
255 ; Informs mascan that we need to write to some slave.
256 ; Some time after this, mascan will call getwritebyte_<everything>
257 ; and this must yield at least one byte to write.
258 ; W slave that we must write to
260 bt_f_if0 cbyte, cbyte_halted
261 return ; we're currently doing something
265 ; wslave slave to write to
266 bc_f cbyte, cbyte_halted
270 goto i2cm_write_start
272 ;----------------------------------------
273 i2c_consider_restartread @
274 bt_f_if0 cbyte, cbyte_halted
276 bra nextslave_nowrite
278 ;======================================================================
282 mov_lw (slavetable + ste_flags) & 0xff
283 ; pretend we've just done us, to start with 1st actual slave
286 bs_f cbyte, cbyte_halted ; serial output of `hello' will start us up
290 mov_lfsr slavetable, 0 ; FSR0 -> slavetable
291 load_tblptr pic2detinfo ; TBLPTR* -> pic2detinfo
292 clr_f t ; t = loop counter
294 tblrd_postinc_fixup ; TABLAT = EOOOOSSS
295 mov_fw TABLAT ; W = EOOOOSSS, N = E
297 tblrd_postinc_fixup ; TABLAT = DSSSSSSS, N (still) = E
298 bra_nn mascan_init_ifabsent
300 mov_ff t, POSTINC0 ; ste_slave = slave
301 mov_wf u ; u = 1OOOOSSS
303 bra_nz mascan_bad_detinfo0
306 mov_fw TABLAT ; W = DSSSSSSS
307 and_lw 0x80 ; W = D0000000
308 mov_wf POSTINC0 ; ste_flags = D0000000
310 mov_fw TABLAT ; W = DSSSSSSS
311 bc_w 7 ; W = 0SSSSSSS = first
312 add_lw -0xf8 ; W = first - 0xf8 = detbasel
313 mov_wf POSTINC0 ; detbasel
315 clr_f POSTINC0 ; lastd0
316 clr_f POSTINC0 ; lastd1
317 clr_f POSTINC0 ; lastd2
318 set_f POSTINC0 ; unused
320 mov_fw u ; W = 10000SSS
321 xor_lw b'10011000' ^ 0x80 ; W = detmsgh
322 mov_wf POSTINC0 ; detmsgh
326 bt_f_if0 t, maxpics_ln2
328 ; we've read the whole flash table
330 if slavetable == 0x400
332 bra mascan_bad_toomany
335 clr_f POSTINC0 ; ste_slave
336 mov_lw (1<<stf_detect)|(1<<stf_sentinel)
337 mov_wf POSTINC0 ; ste_flags
338 ; rest of final entry, and rest of table, is undefined
340 ; at 9600, it's about 1ms per char.
341 ; we allow 1ms to scan 2 pics via i2c.
342 ; so our target len is (no of pics)/2
343 ; plus 2 bytes of slop
346 mov_wf outmsg_targetlen
350 mascan_bad_detinfo0 panic morse_DF
351 mascan_bad_toomany panic morse_DG
353 ;======================================================================
354 ; PROCESSING OF INCOMING BYTES - EXTRA (NON-DETECTION)
357 ;----------------------------------------
369 ;======================================================================
370 ; GENERATION OF DETECTION MESSAGES FOR HOST - MAD BT_F_IF1 TABLES
372 addmsg_testbit macro bit
377 addmsg_return macro dummy_bit
378 goto i2c_arrange_next_byte
381 addmsg_ignore macro dummy_bit
386 addmsg_padding macro dummy_bit
391 ;----------------------------------------
394 ; on entry after first addmsg_one, or when done
395 ; W, STATUS, v, FSR0 undefined trashed
396 ; t adjdetbasel not modified by addmsgs_<kind> or _one
397 ; u [C0]* not modified by addmsgs_<kind> or _one
398 ; b [d0]* not modified by addmsgs_<kind> or _one
399 ; lastd<n> [d0]* (new) not modified by addmsgs_<kind> or _one
400 ; FSR1 -> detmsgh not modified by addmsgs_<kind> or _one
401 ; outbuf, outmsg_* not full, updated appropriately
402 ; all others any not interfered with
404 ; (this is all set up by read_prep_detectbyte and
405 ; read_got_detectbyte_prep_ifsomething)
406 ; when done, branches to i2c_arrange_next_byte, rather than returning
408 addmsgs_section code ( 7 )*4 + 0x2100
411 ; |- PCL bbb value after macro - number in this
412 ; V column should increment 1 each line
414 addmsgs_revhead addmsg_testbit 0
422 addmsgs_all addmsg_testbit 7
432 addmsgs_dethead addmsg_testbit 0
436 addmsg_testbit 6 ; bit 6 was copied to 4 but only in b, not u
441 ; TOS - 4 -> bt_f_if1 w, b'bbb'
443 ; other conditions on entry and exit as for entry to addmsgs_<kind>, above
445 rr_fw TOSL ; W = 0???bbb0
447 ior_wfw 0xf8 ; W = 11111bbb
448 mov_wf FSR0L ; FSR0L = 11111bbb
449 clr_f FSR0H ; FSR0 -> bitnum2bit[bbb]
450 add_wfw t ; W = adjdetbasel + 11111bbb
451 ; ie = 0 SSSSSSS (det msg low byte)
452 mov_wf v ; v = 0 SSSSSSS (det msg low byte)
455 and_wfw INDF0 ; train: W = 0x00, Z=1; none: W = 0*d0*, Z=0
457 mov_lw 0x08 ; train: W = 0 000 0 000; none: W = 0 000 1 000
458 xor_wfw INDF1 ; W = 1 001 Y SSS (det msg high byte)
461 mov_fw v ; W = 0 SSSSSSS (det msg low byte)
462 goto serial_addbyte_another
464 ;======================================================================