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
73 mov_lfsr slavetable, 1
74 mov_ff cslot, FSR1L ; FSR1 -> slave's flags
78 ; this is a first (head) byte:
80 bt_f_if0 POSTINC1, stf_detect ; FSR1 -> detbasel
81 bra read_got_first_reversers
82 read_got_first_detectors ; b = MdBBdddd
83 and_lw 0xb0 ; W = M0BB0000
84 mov_wf cbyte ; cbyte = M0BB0000
85 mov_lw 0x4f ; W = 01001111
86 and_wff b ; b = 0d00dddd
87 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
88 rcall read_got_detectbyte_prep ; b = 0d00dddd
90 bt_f_if1 b, 6 ; b bit .d......
91 bs_f b, 4 ; b = 0d0ddddd
92 ; ^ ^ copies of same bit
93 ; u = (still) 0C00CCCC
94 ; or, using detection segment bit numbers:
100 read_got_first_reversers
102 bra read_got_bad_first_reversers
103 and_lw 0x80 ; W = M0000000
104 mov_wf cbyte ; cbyte = M0000000
105 bc_f b, 7 ; b = 00dddddd
106 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
107 rcall read_got_detectbyte_prep
111 read_got_bad_first_reversers panic morse_MR
114 read_got_detectors_b1 ; b = dddddddd
115 bc_f cbyte, 4 ; cbyte = M0B00000
116 mov_fw POSTINC1 ; W = detbasel; FSR1 -> lastd0
117 inc_f FSR1L ; FSR1 -> lastd1
118 add_lw 5 ; W = detbasel+8
119 rcall read_got_detectbyte_prep
123 read_got_detectors_b2 ; b = dddddddd
124 bc_f cbyte,5 ; cbyte = M0000000
125 mov_fw POSTDEC1 ; W = detbasel; FSR1 -> flags
126 bs_f FSR1L, 2 ; FSR1L -> lastd2
127 add_lw 13 ; W = detbasel+16
128 rcall read_got_detectbyte_prep
132 read_got_detectbyte_prep_ifsomething
134 ; This is a branch of read_got_detectbyte_prep, called if we're doing
135 ; `return' rather than `pop+return'. For conditions on return, see
136 ; read_got_detectbyte_prep; these are supposed to be (basically) the
137 ; same as the entry conditions for addmsgs_<kind>.
149 mov_ff INDF1, xdebug+1
150 xor_wff INDF1 ; lastd<n> = [d0]*
151 ; to force test of repeated detection notification,
152 ; comment out previous line
153 mov_ff INDF1, xdebug+2
155 ior_wff FSR1L ; FSR1L -> detmsgh
156 return ; to addmsgs_<something>, very shortly
158 ;----------------------------------------
161 bra read_got_detectors_b1
163 bra read_got_detectors_b2
164 ; it must be an extra byte
166 bt_f_if0 b, 7 ; any more ?
169 call process_got_extra
170 bra i2c_arrange_next_byte
173 read_got_detectbyte_prep
175 ; Sees if anything has changed. If no changes pops one return address
176 ; and branches to i2c_arrange_next_byte; if some changes, returns to
179 ; So, caller should be i2cmu_read_got_byte, and next stuff
180 ; should basically be a call to addmsg_<something> (perhaps preceded
181 ; by a bit of fiddling of b). addmsg_<something> will finish
182 ; by branching to i2c_arrange_next_byte.
184 ; call return pop+return
185 ; W adjdetbasel preserved undefined
186 ; b [d0]* preserved preserved
187 ; FSR1 -> lastd<n> detmsgh preserved
188 ; cbyte set for next read etc. preserved preserved
189 ; u undefined [C0]* preserved
190 ; lastd<n> [o0]* [d0]* preserved = [d0]*
192 ; TOS -> (optionally, fiddle b, and then:) goto addmsgs_<something>
193 ; NOS return address for i2cmu_read_got_byte
195 mov_wf t ; t = adjdetbasel
197 xor_wfw INDF1 ; W = [C0]*, Z iff same
198 ; where C set iff change to that detection segment
199 bra_nz read_got_detectbyte_prep_ifsomething
200 ; there's nothing to do
203 ;----------------------------------------
204 i2c_arrange_next_byte
206 goto i2cm_read_another
208 ;======================================================================
209 ; DECIDING WHICH SLAVE TO ADDRESS
211 i2c_arrange_something
213 ; figure out what to do next - which pic to address, etc.
214 bs_f cbyte, cbyte_halted
216 tst_f_ifnz wslave ; anyone asked to write ?
219 ; Anyone else to write to ?
220 ; add calls to needwrite_<foo> here:
221 call polarity_needwrite
222 call points_needwrite
223 ; end of list of calls to needwrite_<foo>
225 ; no, if we're here, no-one wants to write:
228 ; no writing needed, we consider reading:
229 bt_f_if1 flags, flags_polarising
230 return ; do not scan while booster PWM is off while polarising
231 ; to avoid all trains disappearing and reappearing
235 and_lw outbuf_size - 1
236 cmp_fw_ifle outmsg_targetlen
237 return ; target len < actual len, do not add anything
238 ; ok, there's space, go ahead:
239 bc_f cbyte, cbyte_halted
242 add_wff cslot ; cslot -> next ste_flags
243 mov_lfsr slavetable, 1 ; FSR1H -> slavetable
244 mov_ff cslot, FSR1L ; FSR1 -> new ste_flags
246 bt_f_if1 POSTDEC1, stf_sentinel ; FSR1 -> ste_slave
247 bra nextslave_looparound
248 ; Ok, we have a slave:
253 mov_fw INDF1 ; W = new slave number
257 ; now we do our own detection
258 mov_lw (slavetable + ste_flags) & 0xff ; select our own slot
263 call read_detection_head_master
264 goto i2cmu_read_got_byte
267 ;----------------------------------------
269 ; Informs mascan that we need to write to some slave.
270 ; Some time after this, mascan will call getwritebyte_<everything>
271 ; and this must yield at least one byte to write.
272 ; W slave that we must write to
274 bt_f_if0 cbyte, cbyte_halted
275 return ; we're currently doing something
279 ; wslave slave to write to
280 bc_f cbyte, cbyte_halted
284 goto i2cm_write_start
286 ;----------------------------------------
287 i2c_consider_restartread @
288 bt_f_if0 cbyte, cbyte_halted
290 bra nextslave_nowrite
292 ;======================================================================
296 mov_lw (slavetable + ste_flags) & 0xff
297 ; pretend we've just done us, to start with 1st actual slave
300 bs_f cbyte, cbyte_halted ; serial output of `hello' will start us up
304 mov_lfsr slavetable, 0 ; FSR0 -> slavetable
305 load_tblptr pic2detinfo ; TBLPTR* -> pic2detinfo
306 clr_f t ; t = loop counter
308 tblrd_postinc_fixup ; TABLAT = EOOOOSSS
309 mov_fw TABLAT ; W = EOOOOSSS, N = E
311 tblrd_postinc_fixup ; TABLAT = DSSSSSSS, N (still) = E
312 bra_nn mascan_init_ifabsent
314 mov_ff t, POSTINC0 ; ste_slave = slave
315 mov_wf u ; u = 1OOOOSSS
317 bra_nz mascan_bad_detinfo0
320 mov_fw TABLAT ; W = DSSSSSSS
321 and_lw 0x80 ; W = D0000000
322 mov_wf POSTINC0 ; ste_flags = D0000000
324 mov_fw TABLAT ; W = DSSSSSSS
325 bc_w 7 ; W = 0SSSSSSS = first
326 add_lw -0xf8 ; W = first - 0xf8 = detbasel
327 mov_wf POSTINC0 ; detbasel
329 clr_f POSTINC0 ; lastd0
330 clr_f POSTINC0 ; lastd1
331 clr_f POSTINC0 ; lastd2
332 set_f POSTINC0 ; unused
334 mov_fw u ; W = 10000SSS
335 xor_lw b'10011000' ^ 0x80 ; W = detmsgh
336 mov_wf POSTINC0 ; detmsgh
340 bt_f_if0 t, maxpics_ln2
342 ; we've read the whole flash table
344 if slavetable == 0x400
346 bra mascan_bad_toomany
349 clr_f POSTINC0 ; ste_slave
350 mov_lw (1<<stf_detect)|(1<<stf_sentinel)
351 mov_wf POSTINC0 ; ste_flags
352 ; rest of final entry, and rest of table, is undefined
354 ; at 9600, it's about 1ms per char.
355 ; we allow 1ms to scan 2 pics via i2c.
356 ; so our target len is (no of pics)/2
357 ; plus 2 bytes of slop
360 mov_wf outmsg_targetlen
364 mascan_bad_detinfo0 panic morse_DF
365 mascan_bad_toomany panic morse_DG
367 ;======================================================================
368 ; PROCESSING OF INCOMING BYTES - EXTRA (NON-DETECTION)
371 ;----------------------------------------
383 ;======================================================================
384 ; GENERATION OF DETECTION MESSAGES FOR HOST - MAD BT_F_IF1 TABLES
386 addmsg_testbit macro bit
391 addmsg_return macro dummy_bit
392 goto i2c_arrange_next_byte
395 addmsg_ignore macro dummy_bit
400 addmsg_padding macro dummy_bit
405 ;----------------------------------------
408 ; on entry after first addmsg_one, or when done
409 ; W, STATUS, v, FSR0 undefined trashed
410 ; t adjdetbasel not modified by addmsgs_<kind> or _one
411 ; u [C0]* not modified by addmsgs_<kind> or _one
412 ; b [d0]* not modified by addmsgs_<kind> or _one
413 ; lastd<n> [d0]* (new) not modified by addmsgs_<kind> or _one
414 ; FSR1 -> detmsgh not modified by addmsgs_<kind> or _one
415 ; outbuf, outmsg_* not full, updated appropriately
416 ; all others any not interfered with
418 ; (this is all set up by read_prep_detectbyte and
419 ; read_got_detectbyte_prep_ifsomething)
420 ; when done, branches to i2c_arrange_next_byte, rather than returning
422 addmsgs_section code ( 7 )*4 + 0x2100
425 ; |- PCL bbb value after macro - number in this
426 ; V column should increment 1 each line
428 addmsgs_revhead addmsg_testbit 0
436 addmsgs_all addmsg_testbit 7
446 addmsgs_dethead addmsg_testbit 0
450 addmsg_testbit 6 ; bit 6 was copied to 4 but only in b, not u
455 ; TOS - 4 -> bt_f_if1 w, b'bbb'
457 ; other conditions on entry and exit as for entry to addmsgs_<kind>, above
462 rr_fw TOSL ; W = 0???bbb0
465 ior_lw 0xf8 ; W = 11111bbb
466 mov_wf FSR0L ; FSR0L = 11111bbb
468 clr_f FSR0H ; FSR0 -> bitnum2bit[bbb]
469 add_wfw t ; W = adjdetbasel + 11111bbb
470 ; ie = 0 SSSSSSS (det msg low byte)
471 mov_wf v ; v = 0 SSSSSSS (det msg low byte)
474 and_wfw INDF0 ; train: W = 0x00, Z=1; none: W = 0*d0*, Z=0
476 mov_lw 0x08 ; train: W = 0 000 0 000; none: W = 0 000 1 000
477 xor_wfw INDF1 ; W = 1 001 Y SSS (det msg high byte)
480 mov_fw v ; W = 0 SSSSSSS (det msg low byte)
481 goto serial_addbyte_another
485 ;======================================================================