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1.1 ! root 1: ;************************************************ ! 2: ; * ! 3: ; EEPROM Write & Read Primitives * ! 4: ; * ! 5: ;************************************************ ! 6: ; ! 7: ; Hi-Score on-board-cartridge EEPROM primitives ! 8: ; for use by Jaguar game cartridge developers. ! 9: ; ! 10: ; 128 bytes (accessable as 64 words) of non-volatile ! 11: ; memory are available on Jaguar game cartridges to ! 12: ; preserve Hi-scores or other game status. ! 13: ; Data is retained for up to 10 years, and a minimum ! 14: ; of 10,000 read/write cycles is assured, according to ! 15: ; product literature. ! 16: ; ! 17: ; ! 18: ; ! 19: ; ! 20: ; ! 21: ; Programmer: Dave Staugas ! 22: ; Atari, Sunnyvale ! 23: ; [408] 745-8802 ! 24: ; ! 25: ; Last Update: 24-Sept-93 ! 26: ; ! 27: ; ! 28: ; Equates needed that may already be defined in the JAGUAR.INC file.. ! 29: ; ! 30: JOY1 equ $f14000 ;this we'll use as our I/O base address ! 31: GPIO_0 equ $f14800 ;General purpose I/O #0 ! 32: GPIO_1 equ $f15000 ;General purpose I/O #1 ! 33: ; ! 34: ; Equates derived from the above ! 35: ; to allow indirect with 16-bit displacement addressing ! 36: ; ! 37: GPIO_0of equ GPIO_0-JOY1 ;offset to GPIO_0 (when addr reg Ax -> JOY1) ! 38: GPIO_1of equ GPIO_1-JOY1 ;offset to GPIO_1 (when addr reg Ax -> JOY1) ! 39: ; ! 40: ; Commands specific to the National Semiconductor NM93C14 ! 41: ; ! 42: ; 9-bit commands.. ! 43: ; 876543210 ! 44: eREAD equ %110000000 ;read from EEPROM ! 45: eEWEN equ %100110000 ;Erase/write Enable ! 46: eWRITE equ %101000000 ;Write selected register ! 47: eEWDS equ %100000000 ;Erase/Write disable (default) ! 48: ; ! 49: ; ! 50: ; DO (data out) - is read on bit0 of JOY1 ! 51: ; DI (data in) - is written on bit0 of GPIO_0 ! 52: ; CS (chip select) - is pulsed low by any access to GPIO_1 ! 53: ; ! 54: ; ! 55: ;***************************************************************** ! 56: ; ! 57: ; Write a word to EEPROM ! 58: ; ! 59: ; entry: d0.w = data to be written ! 60: ; d1.w = least signifigant 6 bits specify write address (0-63) ! 61: ; ! 62: ; exit: all preserved ! 63: ; ! 64: ; ! 65: _eewrite:: ! 66: movem.l a0/d0-d4,-(sp) ! 67: ! 68: move.l 28(sp),d0 ; get data from stack (JDC) ! 69: move.l 32(sp),d1 ; get address from stack (JDC) ! 70: lea JOY1,a0 ;set ptr to EEPROM i/o addresses ! 71: ; ! 72: tst.w GPIO_1of(a0) ;strobe ChipSelect ! 73: ; ! 74: move.w #eEWEN,d2 ;erase/write enable command ! 75: bsr out9bits ;send it to EEPROM ! 76: ; ! 77: tst.w GPIO_1of(a0) ;strobe ChipSelect ! 78: ; ! 79: andi.w #$3f,d1 ;force write addr to be legit (0-63) ! 80: ori.w #eWRITE,d1 ;form WRITE command ! 81: move.w d1,d2 ! 82: bsr out9bits ;send it to EEPROM ! 83: ; ! 84: move.w d0,d2 ;get 16-bit data word to send ! 85: bsr out16bit ; & send it ! 86: ; ! 87: tst.w GPIO_1of(a0) ;strobe ChipSelect ! 88: ; ! 89: nop ;1 us required after CS for status valid ! 90: nop ! 91: move.w #1,d2 ! 92: move.w #$2000,d4 ! 93: wrwait: ! 94: move.w (a0),d3 ;wait until write is complete ! 95: sub.w #1,d4 ; don't stay in here forever ! 96: beq badwrite ; didn't work ! 97: and.w d2,d3 ! 98: beq wrwait ! 99: ; ! 100: move.w #eEWDS,d2 ;get erase/write disable command ! 101: bsr out9bits ;send it ! 102: ; ! 103: tst.w GPIO_1of(a0) ;strobe ChipSelect ! 104: ; ! 105: movem.l (sp)+,a0/d0-d4 ! 106: move.l #1,d0 ; ok write ! 107: rts ;we're done ! 108: ! 109: badwrite: ! 110: movem.l (sp)+,a0/d0-d4 ! 111: move.l #0,d0 ; bad write ! 112: rts ! 113: ! 114: ; ! 115: ; ! 116: ; ! 117: ;****************************************************** ! 118: ; ! 119: ; ! 120: ; Read a word from EEPROM ! 121: ; ! 122: ; entry: d1.w = least signifigant 6 bits specify read address (0-63) ! 123: ; ! 124: ; exit: d0.w = data as read from EEPROM ! 125: ; all other registers preserved ! 126: ; ! 127: _eeread:: ! 128: movem.l a0/d1-d4,-(sp) ! 129: ! 130: move.l 24(sp),d1 ; get address off the stack (JDC) ! 131: lea JOY1,a0 ;set ptr to EEPROM i/o address ! 132: ; ! 133: tst.w GPIO_1of(a0) ;strobe ChipSelect ! 134: ; ! 135: andi.w #$3f,d1 ;force legit read addr ! 136: ori.w #eREAD,d1 ! 137: move.w d1,d2 ! 138: bsr out9bits ! 139: ; ! 140: moveq #0,d0 ! 141: moveq #15,d3 ;pick up 17 bits (1st is dummy) ! 142: inlp: ! 143: tst.w GPIO_0of(a0) ! 144: nop ! 145: move.w (a0),d1 ! 146: lsr.w #1,d1 ! 147: addx.w d0,d0 ! 148: nop ! 149: nop ! 150: nop ! 151: nop ! 152: nop ! 153: nop ! 154: dbra d3,inlp ! 155: ; ! 156: movem.l (sp)+,a0/d1-d4 ! 157: rts ! 158: ; ! 159: ; ! 160: ; ! 161: ;************************************************************** ! 162: ; ! 163: ; Subordinate Routines needed by "eewrite" ! 164: ; ! 165: ; Serial data sent to device is written to DI, bit0 of GPIO_0 ! 166: ; ! 167: ; entry: ! 168: ; a0 -> JOY1 ! 169: ; d2.w = 16-bit data word to write ! 170: ; ! 171: ; exit: ! 172: ; d2.w, d3.l destroyed ! 173: ; ! 174: out16bit: ! 175: rol.w #1,d2 ;align 1st serial data bit (bit15) to bit0 ! 176: moveq #15,d3 ;send 16 bits ! 177: bra.s out9lp ! 178: ; ! 179: ; entry: ! 180: ; a0 -> JOY1 ! 181: ; d2.w = 9-bit command to write ! 182: ; ! 183: out9bits: ! 184: rol.w #8,d2 ;align 1st serial data bit (bit8) to bit0 ! 185: moveq #8,d3 ;send 9 ! 186: out9lp: ! 187: move.w d2,GPIO_0of(a0) ;write next bit ! 188: nop ! 189: nop ! 190: nop ;delay next write ! 191: nop ! 192: nop ! 193: nop ! 194: rol.w #1,d2 ;adjust bit0 for next datum ! 195: dbra d3,out9lp ;go for all 9 or all 16 ! 196: rts ! 197: ; ! 198: ;
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