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1 | ############################################################################### |
| 2 | # |
| 3 | # Copyright (c) 2011, GraÅžvydas Ignotas |
| 4 | # All rights reserved. |
| 5 | # |
| 6 | # Redistribution and use in source and binary forms, with or without |
| 7 | # modification, are permitted provided that the following conditions are met: |
| 8 | # * Redistributions of source code must retain the above copyright |
| 9 | # notice, this list of conditions and the following disclaimer. |
| 10 | # * Redistributions in binary form must reproduce the above copyright |
| 11 | # notice, this list of conditions and the following disclaimer in the |
| 12 | # documentation and/or other materials provided with the distribution. |
| 13 | # * Neither the name of the organization nor the |
| 14 | # names of its contributors may be used to endorse or promote products |
| 15 | # derived from this software without specific prior written permission. |
| 16 | # |
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17 | # THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND ANY |
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18 | # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 19 | # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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20 | # DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY |
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21 | # DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 22 | # (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 23 | # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| 24 | # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 26 | # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | # |
| 28 | # Assemble with gas |
| 29 | # --register-prefix-optional --bitwise-or |
| 30 | # |
| 31 | |
| 32 | #include "transfer.h" |
| 33 | |
| 34 | .text |
| 35 | .globl do_transfer |
| 36 | |
| 37 | |
| 38 | # receive 1 byte to d0 |
| 39 | # in: a1 - data port |
| 40 | # trash: d1 |
| 41 | .macro recv_one_byte is_last=0 |
| 42 | move.b #0,(a1) /* clear TH */ |
| 43 | |
| 44 | 0: /*L_wait_tl_low*/ |
| 45 | move.b (a1),d1 |
| 46 | btst.b #4,d1 |
| 47 | bne 0b /*L_wait_tl_low*/ |
| 48 | |
| 49 | move.b #0x40,(a1) /* set TH */ |
| 50 | and.b #0x0f,d1 |
| 51 | |
| 52 | 0: /*L_wait_tl_hi*/ |
| 53 | move.b (a1),d0 |
| 54 | btst.b #4,d0 |
| 55 | beq 0b /*L_wait_tl_hi*/ |
| 56 | |
| 57 | .if !\is_last |
| 58 | move.b #0,(a1) /* clear TH - ready for next */ |
| 59 | .endif |
| 60 | lsl.b #4,d0 |
| 61 | or.b d1,d0 |
| 62 | .endm |
| 63 | |
| 64 | # send 1 byte in d0 |
| 65 | # in: a1 - data port |
| 66 | # trash: d1,d2 |
| 67 | .macro send_one_byte |
| 68 | move.b d0,d2 |
| 69 | and.b #0x0f,d2 |
| 70 | |
| 71 | 0: /*Lwait_tl_low:*/ |
| 72 | move.b (a1),d1 |
| 73 | btst.b #4,d1 |
| 74 | bne 0b /*Lwait_tl_low*/ |
| 75 | |
| 76 | move.b d2,(a1) /* clears TH and writes data */ |
| 77 | |
| 78 | move.b d0,d2 |
| 79 | lsr.b #4,d2 |
| 80 | bset.b #6,d2 /* prepare TH */ |
| 81 | |
| 82 | 0: /*wait_tl_hi*/ |
| 83 | move.b (a1),d1 |
| 84 | btst.b #4,d1 |
| 85 | beq 0b /*wait_tl_hi1*/ |
| 86 | |
| 87 | move.b d2,(a1) |
| 88 | .endm |
| 89 | |
| 90 | recv_byte: |
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91 | moveq.l #0,d0 |
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92 | recv_one_byte 1 |
| 93 | rts |
| 94 | |
| 95 | # receive address/size to d0 (3 bytes BE) |
| 96 | # in: a1 - data port |
| 97 | # trash: d1,d2 |
| 98 | recv_ad: |
| 99 | moveq.l #0,d2 |
| 100 | bsr recv_byte |
| 101 | move.b d0,d2 |
| 102 | bsr recv_byte |
| 103 | lsl.l #8,d2 |
| 104 | move.b d0,d2 |
| 105 | bsr recv_byte |
| 106 | lsl.l #8,d2 |
| 107 | move.b d0,d2 |
| 108 | move.l d2,d0 |
| 109 | rts |
| 110 | |
| 111 | |
| 112 | do_transfer: |
| 113 | lea 0xa10005,a1 |
| 114 | move.b #0x40,(0xa1000b).l /* ctrl - all inputs except TH */ |
| 115 | move.b #0x00,(a1) |
| 116 | |
| 117 | bsr recv_byte |
| 118 | cmp.b #CMD_PREFIX,d0 |
| 119 | bne return |
| 120 | |
| 121 | bsr recv_byte |
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122 | cmp.b #CMD_FIRST,d0 |
| 123 | bcs return |
| 124 | cmp.b #CMD_LAST+1,d0 |
| 125 | bcc return |
| 126 | sub.b #CMD_FIRST,d0 |
| 127 | |
| 128 | lsl.w #2,d0 |
| 129 | lea (jumptab,pc,d0),a0 |
| 130 | jmp (a0) |
| 131 | jumptab: |
| 132 | bra pcc_transfer_recv /* sent to us */ |
| 133 | bra pcc_transfer_send /* recv from us */ |
| 134 | bra pcc_jump |
| 135 | bra pcc_test_code |
| 136 | |
| 137 | |
| 138 | pcc_transfer_recv: |
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139 | bsr recv_ad |
| 140 | move.l d0,a0 |
| 141 | bsr recv_ad |
| 142 | move.l d0,d3 |
| 143 | |
| 144 | tr_recv_loop: |
| 145 | recv_one_byte |
| 146 | move.b d0,(a0)+ |
| 147 | subq.l #1,d3 |
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148 | bgt tr_recv_loop |
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149 | bra return |
| 150 | |
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151 | |
| 152 | pcc_transfer_send: |
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153 | bsr recv_ad |
| 154 | move.l d0,a0 |
| 155 | bsr recv_ad |
| 156 | move.l d0,d3 |
| 157 | |
| 158 | 0: /*Lwait_tl_low:*/ |
| 159 | move.b (a1),d0 |
| 160 | btst.b #4,d0 |
| 161 | bne 0b /*Lwait_tl_low*/ |
| 162 | |
| 163 | move.b #0x4f,(0xa1000b).l |
| 164 | move.b #0x40,(a1) |
| 165 | |
| 166 | tr_send_loop: |
| 167 | move.b (a0)+,d0 |
| 168 | send_one_byte |
| 169 | subq.l #1,d3 |
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170 | bgt tr_send_loop |
| 171 | bra return |
| 172 | |
| 173 | |
| 174 | pcc_jump: |
| 175 | bsr recv_ad |
| 176 | move.l d0,a0 |
| 177 | jmp (a0) |
| 178 | |
| 179 | |
| 180 | pcc_test_code: |
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181 | bra return |
| 182 | |
| 183 | |
| 184 | return: |
| 185 | move.b #0,(0xa1000b).l /* all inputs */ |
| 186 | move.l #0xffe000,a1 |
| 187 | move.l d0,(a1)+ /* last state for debug */ |
| 188 | move.l d1,(a1)+ |
| 189 | move.l d2,(a1)+ |
| 190 | move.l d3,(a1)+ |
| 191 | move.l a0,(a1)+ |
| 192 | bra return_to_main |
| 193 | |
| 194 | |
| 195 | # vim:filetype=asmM68k |
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