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.
54 call i2cm_interrupt_definite
57 ;======================================================================
58 ; PROCESSING OF INCOMING BYTES - CORE AND DETECTION
60 ;----------------------------------------
63 ; State Reading Reading-Wait
66 ; See detect.asm head comment for protocol info, in particular
67 ; the meaning of these bytes.
69 mov_wf b ; W = b = received byte
71 mov_lfsr slavetable, 1
72 mov_ff cslot, FSR1L ; FSR1 -> slave's flags
76 ; this is a first (head) byte:
78 bt_f_if0 POSTINC1, stf_detect ; FSR1 -> detbasel
79 bra read_got_first_reversers
80 read_got_first_detectors ; b = MdBBdddd
81 and_lw 0xb0 ; W = M0BB0000
82 mov_wf cbyte ; cbyte = M0BB0000
83 mov_lw 0x4f ; W = 01001111
84 and_wff b ; b = 0d00dddd
85 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
86 rcall read_got_detectbyte_prep ; b = 0d00dddd
88 bt_f_if1 b, 6 ; b bit .d......
89 bs_f b, 4 ; b = 0d0ddddd
90 ; ^ ^ copies of same bit
91 ; u = (still) 0C00CCCC
92 ; or, using detection segment bit numbers:
98 read_got_first_reversers
100 bra read_got_bad_first_reversers
101 and_lw 0x80 ; W = M0000000
102 mov_wf cbyte ; cbyte = M0000000
103 bc_f b, 7 ; b = 00dddddd
104 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
105 rcall read_got_detectbyte_prep
109 read_got_bad_first_reversers panic morse_MR
112 read_got_detectors_b1 ; b = dddddddd
113 bc_f cbyte, 4 ; cbyte = M0B00000
114 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
115 inc_f FSR1L ; FSR1 -> lastd1
116 add_lw 5 ; W = detbasel+8
117 rcall read_got_detectbyte_prep
121 read_got_detectors_b2 ; b = dddddddd
122 bc_f cbyte,5 ; cbyte = M0000000
123 mov_fw POSTDEC1 ; W = detbasel; FSR1 -> flags
124 bs_f FSR1L, 2 ; FSR1L -> lastd2
125 add_lw 13 ; W = detbasel+16
126 rcall read_got_detectbyte_prep
130 read_got_detectbyte_prep_ifsomething
132 ; This is a branch of read_got_detectbyte_prep, called if we're doing
133 ; `return' rather than `pop+return'. For conditions on return, see
134 ; read_got_detectbyte_prep; these are supposed to be (basically) the
135 ; same as the entry conditions for addmsgs_<kind>.
146 xor_wfw INDF1 ; lastd<n> = [d0]*
148 ior_wff FSR1L ; FSR1L -> detmsgh
149 return ; to addmsgs_<something>, very shortly
151 ;----------------------------------------
154 bra read_got_detectors_b1
156 bra read_got_detectors_b2
157 ; it must be an extra byte
159 bt_f_if0 b, 7 ; any more ?
162 call process_got_extra
163 bra i2c_arrange_next_byte
166 read_got_detectbyte_prep
168 ; Sees if anything has changed. If no changes pops one return address
169 ; and branches to i2c_arrange_next_byte; if some changes, returns to
172 ; So, caller should be i2cmu_read_got_byte, and next stuff
173 ; should basically be a call to addmsg_<something> (perhaps preceded
174 ; by a bit of fiddling of b). addmsg_<something> will finish
175 ; by branching to i2c_arrange_next_byte.
177 ; call return pop+return
178 ; W adjdetbasel preserved undefined
179 ; b [d0]* preserved preserved
180 ; FSR1 -> lastd<n> detmsgh preserved
181 ; cbyte set for next read etc. preserved preserved
182 ; u undefined [C0]* preserved
183 ; lastd<n> [o0]* [d0]* preserved = [d0]*
185 ; TOS -> (optionally, fiddle b, and then:) goto addmsgs_<something>
186 ; NOS return address for i2cmu_read_got_byte
188 mov_wf t ; t = adjdetbasel
190 xor_wfw INDF1 ; W = [C0]*, Z iff same
191 ; where C set iff change to that detection segment
192 bra_nz read_got_detectbyte_prep_ifsomething
193 ; there's nothing to do
196 ;----------------------------------------
197 i2c_arrange_next_byte
199 goto i2cm_read_another
201 ;======================================================================
202 ; DECIDING WHICH SLAVE TO ADDRESS
204 i2c_arrange_something
206 ; figure out what to do next - which pic to address, etc.
207 bs_f cbyte, cbyte_halted
209 tst_f_ifnz wslave ; anyone asked to write ?
212 ; Anyone else to write to ?
213 ; add calls to needwrite_<foo> here:
214 call polarity_needwrite
215 call points_needwrite
216 ; end of list of calls to needwrite_<foo>
218 ; no, if we're here, no-one wants to write:
222 ; no writing needed, we consider reading:
223 bt_f_if1 flags, flags_polarising
224 return ; do not scan while booster PWM is off while polarising
225 ; to avoid all trains disappearing and reappearing
227 return ; do not scan yet
231 and_lw outbuf_size - 1
232 cmp_fw_ifle outmsg_targetlen
233 return ; target len < actual len, do not add anything
234 ; ok, there's space, go ahead:
235 bc_f cbyte, cbyte_halted
238 add_wff cslot ; cslot -> next ste_flags
239 mov_lfsr slavetable, 1 ; FSR1H -> slavetable
240 mov_ff cslot, FSR1L ; FSR1 -> new ste_flags
242 bt_f_if1 POSTDEC1, stf_sentinel ; FSR1 -> ste_slave
243 bra nextslave_looparound
244 ; Ok, we have a slave:
246 mov_fw INDF1 ; W = new slave number
250 ; now we do our own detection
251 mov_lw (slavetable + ste_flags) & 0xff ; select our own slot
253 call read_detection_head_master
254 goto i2cmu_read_got_byte
257 ;----------------------------------------
259 ; Informs mascan that we need to write to some slave.
260 ; Some time after this, mascan will call getwritebyte_<everything>
261 ; and this must yield at least one byte to write.
262 ; W slave that we must write to
264 bt_f_if0 cbyte, cbyte_halted
265 return ; we're currently doing something
269 ; wslave slave to write to
271 bc_f cbyte, cbyte_halted
275 goto i2cm_write_start
277 ;----------------------------------------
278 i2c_consider_restartread @
279 bt_f_if0 cbyte, cbyte_halted
281 bra nextslave_nowrite
283 ;======================================================================
287 mov_lw (slavetable + ste_flags + ste_size) & 0xff
288 ; start with 1st actual slave
291 bs_f cbyte, cbyte_halted ; serial output of `hello' will start us up
295 mov_lfsr slavetable, 0 ; FSR0 -> slavetable
296 load_tblptr pic2detinfo ; TBLPTR* -> pic2detinfo
297 clr_f t ; t = loop counter
299 tblrd_postinc_fixup ; TABLAT = EOOOOSSS
300 mov_fw TABLAT ; W = EOOOOSSS, N = E
302 tblrd_postinc_fixup ; TABLAT = DSSSSSSS, N (still) = E
303 bra_nn mascan_init_ifabsent
305 mov_ff t, POSTINC0 ; ste_slave = slave
306 mov_wf u ; u = 1OOOOSSS
308 bra_nz mascan_bad_detinfo0
311 mov_fw TABLAT ; W = DSSSSSSS
312 and_lw 0x80 ; W = D0000000
313 mov_wf POSTINC0 ; ste_flags = D0000000
315 mov_fw TABLAT ; W = DSSSSSSS
316 bc_w 7 ; W = 0SSSSSSS = first
317 add_lw -0xf8 ; W = first - 0xf8 = detbasel
318 mov_wf POSTINC0 ; detbasel
320 clr_f POSTINC0 ; lastd0
321 clr_f POSTINC0 ; lastd1
322 clr_f POSTINC0 ; lastd2
323 set_f POSTINC0 ; unused
325 mov_fw u ; W = 10000SSS
326 xor_lw b'10011000' ^ 0x80 ; W = detmsgh
327 mov_wf POSTINC0 ; detmsgh
331 bt_f_if0 t, maxpics_ln2
333 ; we've read the whole flash table
335 if slavetable == 0x400
337 bra mascan_bad_toomany
340 clr_f POSTINC0 ; ste_slave
341 mov_lw (1<<stf_detect)|(1<<stf_sentinel)
342 mov_wf POSTINC0 ; ste_flags
343 ; rest of final entry, and rest of table, is undefined
345 ; at 9600, it's about 1ms per char.
346 ; we allow 1ms to scan 2 pics via i2c.
347 ; so our target len is (no of pics)/2
348 ; plus 2 bytes of slop
351 mov_wf outmsg_targetlen
355 mascan_bad_detinfo0 panic morse_DF
356 mascan_bad_toomany panic morse_DG
358 ;======================================================================
359 ; PROCESSING OF INCOMING BYTES - EXTRA (NON-DETECTION)
362 ;----------------------------------------
374 ;======================================================================
375 ; GENERATION OF DETECTION MESSAGES FOR HOST - MAD BT_F_IF1 TABLES
377 addmsg_testbit macro bit
382 addmsg_return macro dummy_bit
383 goto i2c_arrange_next_byte
386 addmsg_ignore macro dummy_bit
391 addmsg_padding macro dummy_bit
396 ;----------------------------------------
399 ; on entry after first addmsg_one, or when done
400 ; W, STATUS, v, FSR0 undefined trashed
401 ; t adjdetbasel not modified by addmsgs_<kind> or _one
402 ; u [C0]* not modified by addmsgs_<kind> or _one
403 ; b [d0]* not modified by addmsgs_<kind> or _one
404 ; lastd<n> [d0]* (new) not modified by addmsgs_<kind> or _one
405 ; FSR1 -> detmsgh not modified by addmsgs_<kind> or _one
406 ; outbuf, outmsg_* not full, updated appropriately
407 ; all others any not interfered with
409 ; (this is all set up by read_prep_detectbyte and
410 ; read_got_detectbyte_prep_ifsomething)
411 ; when done, branches to i2c_arrange_next_byte, rather than returning
413 addmsgs_section code ( 7 )*4 + 0x2100
416 ; |- PCL bbb value after macro - number in this
417 ; V column should increment 1 each line
419 addmsgs_revhead addmsg_testbit 0
427 addmsgs_all addmsg_testbit 7
437 addmsgs_dethead addmsg_testbit 0
441 addmsg_testbit 6 ; bit 6 was copied to 4 but only in b, not u
446 ; TOS - 4 -> bt_f_if1 w, b'bbb'
448 ; other conditions on entry and exit as for entry to addmsgs_<kind>, above
449 rr_fw TOSL ; W = 0???bbb0
451 ior_wfw 0xf8 ; W = 11111bbb
452 mov_wf FSR0L ; FSR0L = 11111bbb
453 clr_f FSR0H ; FSR0 -> bitnum2bit[bbb]
454 add_wfw t ; W = adjdetbasel + 11111bbb
455 ; ie = 0 SSSSSSS (det msg low byte)
456 mov_wf v ; v = 0 SSSSSSS (det msg low byte)
459 and_wfw INDF0 ; train: W = 0x00, Z=1; none: W = 0*d0*, Z=0
461 mov_lw 0x08 ; train: W = 0 000 0 000; none: W = 0 000 1 000
462 xor_wfw INDF1 ; W = 1 001 Y SSS (det msg high byte)
465 mov_fw v ; W = 0 SSSSSSS (det msg low byte)
466 goto serial_addbyte_another
468 ;======================================================================