Sungjin Park
c
mcp2515_bittime.h@0:d8f50b1e384f, 2010-01-30 (annotated)
- Committer:
- tecnosys
- Date:
- Sat Jan 30 08:46:04 2010 +0000
- Revision:
- 0:d8f50b1e384f
- Child:
- 1:dbc44582f2f8
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| tecnosys | 0:d8f50b1e384f | 1 | /****************************************************************************** |
| tecnosys | 0:d8f50b1e384f | 2 | * |
| tecnosys | 0:d8f50b1e384f | 3 | * Controller Area Network (CAN) Demo-Application |
| tecnosys | 0:d8f50b1e384f | 4 | * Atmel AVR with Microchip MCP2515 |
| tecnosys | 0:d8f50b1e384f | 5 | * |
| tecnosys | 0:d8f50b1e384f | 6 | * Copyright (C) 2005 Martin THOMAS, Kaiserslautern, Germany |
| tecnosys | 0:d8f50b1e384f | 7 | * <eversmith@heizung-thomas.de> |
| tecnosys | 0:d8f50b1e384f | 8 | * http://www.siwawi.arubi.uni-kl.de/avr_projects |
| tecnosys | 0:d8f50b1e384f | 9 | * |
| tecnosys | 0:d8f50b1e384f | 10 | ***************************************************************************** |
| tecnosys | 0:d8f50b1e384f | 11 | * |
| tecnosys | 0:d8f50b1e384f | 12 | * File : mcp2515_bittime.h |
| tecnosys | 0:d8f50b1e384f | 13 | * Version : 0.9 |
| tecnosys | 0:d8f50b1e384f | 14 | * |
| tecnosys | 0:d8f50b1e384f | 15 | * Summary : MCP2515 CAN-timing values. Calculated with |
| tecnosys | 0:d8f50b1e384f | 16 | * a spreadsheet-based "Preprocessor" with information |
| tecnosys | 0:d8f50b1e384f | 17 | * from the MCP2515 and AT90CAN128 datasheets. |
| tecnosys | 0:d8f50b1e384f | 18 | * |
| tecnosys | 0:d8f50b1e384f | 19 | *****************************************************************************/ |
| tecnosys | 0:d8f50b1e384f | 20 | |
| tecnosys | 0:d8f50b1e384f | 21 | #include "mcp2515_defs.h" |
| tecnosys | 0:d8f50b1e384f | 22 | |
| tecnosys | 0:d8f50b1e384f | 23 | /*-----------------------*/ |
| tecnosys | 0:d8f50b1e384f | 24 | /* global settings */ |
| tecnosys | 0:d8f50b1e384f | 25 | /*-----------------------*/ |
| tecnosys | 0:d8f50b1e384f | 26 | |
| tecnosys | 0:d8f50b1e384f | 27 | /* CFG3 */ |
| tecnosys | 0:d8f50b1e384f | 28 | |
| tecnosys | 0:d8f50b1e384f | 29 | // Start of Frame SOF (CLKOUT) |
| tecnosys | 0:d8f50b1e384f | 30 | // either SOF_ENABLE or SOF_DISABLE |
| tecnosys | 0:d8f50b1e384f | 31 | #define MCP_GENERAL_SOF (SOF_DISABLE) |
| tecnosys | 0:d8f50b1e384f | 32 | |
| tecnosys | 0:d8f50b1e384f | 33 | // Wake up Filter (WAKFIL) |
| tecnosys | 0:d8f50b1e384f | 34 | // either WAKFIL_ENABLE or WAKFIL_DISABLE |
| tecnosys | 0:d8f50b1e384f | 35 | #define MCP_GENERAL_WAKFIL (WAKFIL_DISABLE) |
| tecnosys | 0:d8f50b1e384f | 36 | |
| tecnosys | 0:d8f50b1e384f | 37 | |
| tecnosys | 0:d8f50b1e384f | 38 | /*-----------------------*/ |
| tecnosys | 0:d8f50b1e384f | 39 | /* 125 kBPS @ 4MHZ F_OSC */ |
| tecnosys | 0:d8f50b1e384f | 40 | /*-----------------------*/ |
| tecnosys | 0:d8f50b1e384f | 41 | |
| tecnosys | 0:d8f50b1e384f | 42 | /* CNF1 */ |
| tecnosys | 0:d8f50b1e384f | 43 | |
| tecnosys | 0:d8f50b1e384f | 44 | // SJW as defined in mcp_defs.h |
| tecnosys | 0:d8f50b1e384f | 45 | // here: SJW = 1*TQ |
| tecnosys | 0:d8f50b1e384f | 46 | #define MCP_4MHz_125kBPS_SJW (SJW1) |
| tecnosys | 0:d8f50b1e384f | 47 | |
| tecnosys | 0:d8f50b1e384f | 48 | // Prescaler = (BRP+1)*2 |
| tecnosys | 0:d8f50b1e384f | 49 | // here Prescaler = 4 -> BRP=1 |
| tecnosys | 0:d8f50b1e384f | 50 | #define MCP_4MHz_125kBPS_BRP (1) |
| tecnosys | 0:d8f50b1e384f | 51 | |
| tecnosys | 0:d8f50b1e384f | 52 | |
| tecnosys | 0:d8f50b1e384f | 53 | /* CNF2 */ |
| tecnosys | 0:d8f50b1e384f | 54 | |
| tecnosys | 0:d8f50b1e384f | 55 | // BLT-Mode defined in CNF3 (0 or BTLMODE from mcp_defs.h) |
| tecnosys | 0:d8f50b1e384f | 56 | #define MCP_4MHz_125kBPS_BLTMODE (BTLMODE) |
| tecnosys | 0:d8f50b1e384f | 57 | |
| tecnosys | 0:d8f50b1e384f | 58 | // 3 samples (SAMPLE_3X) or 1 sample (SAMPLE_1X) |
| tecnosys | 0:d8f50b1e384f | 59 | #define MCP_4MHz_125kBPS_SAM (SAMPLE_1X) |
| tecnosys | 0:d8f50b1e384f | 60 | |
| tecnosys | 0:d8f50b1e384f | 61 | // (Phase Segment 1) PHSEG1 = PS1 - 1 |
| tecnosys | 0:d8f50b1e384f | 62 | // here: PS1 calculated as 2 |
| tecnosys | 0:d8f50b1e384f | 63 | #define MCP_4MHz_125kBPS_PHSEG1 ((2-1)<<3) |
| tecnosys | 0:d8f50b1e384f | 64 | |
| tecnosys | 0:d8f50b1e384f | 65 | // (Propagation Delay) PRSEG = PRSEQTQ-1 |
| tecnosys | 0:d8f50b1e384f | 66 | // here PRSEQTQ = 2 |
| tecnosys | 0:d8f50b1e384f | 67 | #define MCP_4MHz_125kBPS_PRSEG (2-1) |
| tecnosys | 0:d8f50b1e384f | 68 | |
| tecnosys | 0:d8f50b1e384f | 69 | /* CNF3 */ |
| tecnosys | 0:d8f50b1e384f | 70 | |
| tecnosys | 0:d8f50b1e384f | 71 | // (Phase Segment 2) PHSEG2 = PS2 - 1 |
| tecnosys | 0:d8f50b1e384f | 72 | // here: PS2 calculated as 3 |
| tecnosys | 0:d8f50b1e384f | 73 | #define MCP_4MHz_125kBPS_PHSEG (3-1) |
| tecnosys | 0:d8f50b1e384f | 74 | |
| tecnosys | 0:d8f50b1e384f | 75 | |
| tecnosys | 0:d8f50b1e384f | 76 | #define MCP_4MHz_125kBPS_CFG1 (MCP_4MHz_125kBPS_SJW | MCP_4MHz_125kBPS_BRP) |
| tecnosys | 0:d8f50b1e384f | 77 | #define MCP_4MHz_125kBPS_CFG2 (MCP_4MHz_125kBPS_BLTMODE | MCP_4MHz_125kBPS_SAM | \ |
| tecnosys | 0:d8f50b1e384f | 78 | MCP_4MHz_125kBPS_PHSEG1 | MCP_4MHz_125kBPS_PRSEG) |
| tecnosys | 0:d8f50b1e384f | 79 | #define MCP_4MHz_125kBPS_CFG3 (MCP_GENERAL_SOF | MCP_GENERAL_WAKFIL | \ |
| tecnosys | 0:d8f50b1e384f | 80 | MCP_4MHz_125kBPS_PHSEG) |
| tecnosys | 0:d8f50b1e384f | 81 | |
| tecnosys | 0:d8f50b1e384f | 82 | |
| tecnosys | 0:d8f50b1e384f | 83 | /*-----------------------*/ |
| tecnosys | 0:d8f50b1e384f | 84 | /* 20 kBPS @ 4MHZ F_OSC */ |
| tecnosys | 0:d8f50b1e384f | 85 | /*-----------------------*/ |
| tecnosys | 0:d8f50b1e384f | 86 | |
| tecnosys | 0:d8f50b1e384f | 87 | /* CNF1 */ |
| tecnosys | 0:d8f50b1e384f | 88 | |
| tecnosys | 0:d8f50b1e384f | 89 | // SJW as defined in mcp_defs.h |
| tecnosys | 0:d8f50b1e384f | 90 | // here: SJW = 1*TQ |
| tecnosys | 0:d8f50b1e384f | 91 | #define MCP_4MHz_20kBPS_SJW (SJW1) |
| tecnosys | 0:d8f50b1e384f | 92 | |
| tecnosys | 0:d8f50b1e384f | 93 | // Prescaler = (BRP+1)*2 |
| tecnosys | 0:d8f50b1e384f | 94 | // here Prescaler = 10 -> BRP=4 (20TQ) |
| tecnosys | 0:d8f50b1e384f | 95 | #define MCP_4MHz_20kBPS_BRP (4) |
| tecnosys | 0:d8f50b1e384f | 96 | |
| tecnosys | 0:d8f50b1e384f | 97 | |
| tecnosys | 0:d8f50b1e384f | 98 | /* CNF2 */ |
| tecnosys | 0:d8f50b1e384f | 99 | |
| tecnosys | 0:d8f50b1e384f | 100 | // BLT-Mode defined in CNF3 (0 or BTLMODE from mcp_defs.h) |
| tecnosys | 0:d8f50b1e384f | 101 | #define MCP_4MHz_20kBPS_BLTMODE (BTLMODE) |
| tecnosys | 0:d8f50b1e384f | 102 | |
| tecnosys | 0:d8f50b1e384f | 103 | // 3 samples (SAMPLE_1X) or 1 sample (SAMPLE_1X) |
| tecnosys | 0:d8f50b1e384f | 104 | #define MCP_4MHz_20kBPS_SAM (SAMPLE_1X) |
| tecnosys | 0:d8f50b1e384f | 105 | |
| tecnosys | 0:d8f50b1e384f | 106 | // (Phase Segment 1) PHSEG1 = PS1 - 1 |
| tecnosys | 0:d8f50b1e384f | 107 | // here: PS1 calculated as 8 |
| tecnosys | 0:d8f50b1e384f | 108 | #define MCP_4MHz_20kBPS_PHSEG1 ((8-1)<<3) |
| tecnosys | 0:d8f50b1e384f | 109 | |
| tecnosys | 0:d8f50b1e384f | 110 | // (Propagation Delay) PRSEG = PRSEQTQ-1 |
| tecnosys | 0:d8f50b1e384f | 111 | // here PRSEQTQ = 3 |
| tecnosys | 0:d8f50b1e384f | 112 | #define MCP_4MHz_20kBPS_PRSEG (3-1) |
| tecnosys | 0:d8f50b1e384f | 113 | |
| tecnosys | 0:d8f50b1e384f | 114 | /* CNF3 */ |
| tecnosys | 0:d8f50b1e384f | 115 | |
| tecnosys | 0:d8f50b1e384f | 116 | // (Phase Segment 2) PHSEG2 = PS2 - 1 |
| tecnosys | 0:d8f50b1e384f | 117 | // here: PS2 calculated as 8 |
| tecnosys | 0:d8f50b1e384f | 118 | #define MCP_4MHz_20kBPS_PHSEG (8-1) |
| tecnosys | 0:d8f50b1e384f | 119 | |
| tecnosys | 0:d8f50b1e384f | 120 | |
| tecnosys | 0:d8f50b1e384f | 121 | #define MCP_4MHz_20kBPS_CFG1 (MCP_4MHz_20kBPS_SJW | MCP_4MHz_20kBPS_BRP) |
| tecnosys | 0:d8f50b1e384f | 122 | #define MCP_4MHz_20kBPS_CFG2 (MCP_4MHz_20kBPS_BLTMODE | MCP_4MHz_20kBPS_SAM | \ |
| tecnosys | 0:d8f50b1e384f | 123 | MCP_4MHz_20kBPS_PHSEG1 | MCP_4MHz_20kBPS_PRSEG) |
| tecnosys | 0:d8f50b1e384f | 124 | #define MCP_4MHz_20kBPS_CFG3 (MCP_GENERAL_SOF | MCP_GENERAL_WAKFIL | \ |
| tecnosys | 0:d8f50b1e384f | 125 | MCP_4MHz_20kBPS_PHSEG) |