Diff: mcp2515_bittime.h

Revision:

0:d8f50b1e384f

Child:

1:dbc44582f2f8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mcp2515_bittime.h	Sat Jan 30 08:46:04 2010 +0000
@@ -0,0 +1,125 @@
+/******************************************************************************
+ * 
+ * Controller Area Network (CAN) Demo-Application
+ * Atmel AVR with Microchip MCP2515 
+ * 
+ * Copyright (C) 2005 Martin THOMAS, Kaiserslautern, Germany
+ * <eversmith@heizung-thomas.de>
+ * http://www.siwawi.arubi.uni-kl.de/avr_projects
+ *
+ *****************************************************************************
+ *
+ * File    : mcp2515_bittime.h
+ * Version : 0.9
+ * 
+ * Summary : MCP2515 CAN-timing values. Calculated with 
+ *           a spreadsheet-based "Preprocessor" with information
+ *           from the MCP2515 and AT90CAN128 datasheets.
+ *
+ *****************************************************************************/
+
+#include "mcp2515_defs.h"
+
+/*-----------------------*/
+/* global settings       */
+/*-----------------------*/
+
+/* CFG3 */
+
+// Start of Frame SOF (CLKOUT)
+// either SOF_ENABLE or SOF_DISABLE
+#define MCP_GENERAL_SOF (SOF_DISABLE)
+
+// Wake up Filter (WAKFIL)
+// either WAKFIL_ENABLE    or WAKFIL_DISABLE
+#define MCP_GENERAL_WAKFIL (WAKFIL_DISABLE)
+
+
+/*-----------------------*/
+/* 125 kBPS @ 4MHZ F_OSC */
+/*-----------------------*/
+
+/* CNF1 */
+
+// SJW as defined in mcp_defs.h
+// here: SJW = 1*TQ
+#define MCP_4MHz_125kBPS_SJW (SJW1)
+
+// Prescaler = (BRP+1)*2
+// here Prescaler = 4 -> BRP=1
+#define MCP_4MHz_125kBPS_BRP (1)
+
+
+/* CNF2 */
+
+// BLT-Mode defined in CNF3 (0 or BTLMODE from mcp_defs.h)
+#define MCP_4MHz_125kBPS_BLTMODE (BTLMODE)
+
+// 3 samples (SAMPLE_3X) or 1 sample (SAMPLE_1X)
+#define MCP_4MHz_125kBPS_SAM   (SAMPLE_1X)
+
+// (Phase Segment 1) PHSEG1 = PS1 - 1
+// here: PS1 calculated as 2 
+#define MCP_4MHz_125kBPS_PHSEG1 ((2-1)<<3)
+
+// (Propagation Delay) PRSEG = PRSEQTQ-1
+// here PRSEQTQ = 2
+#define MCP_4MHz_125kBPS_PRSEG (2-1)
+
+/* CNF3 */
+
+// (Phase Segment 2) PHSEG2 = PS2 - 1
+// here: PS2 calculated as 3
+#define MCP_4MHz_125kBPS_PHSEG (3-1)
+
+
+#define MCP_4MHz_125kBPS_CFG1 (MCP_4MHz_125kBPS_SJW | MCP_4MHz_125kBPS_BRP)
+#define MCP_4MHz_125kBPS_CFG2 (MCP_4MHz_125kBPS_BLTMODE | MCP_4MHz_125kBPS_SAM | \
+                MCP_4MHz_125kBPS_PHSEG1 | MCP_4MHz_125kBPS_PRSEG)
+#define MCP_4MHz_125kBPS_CFG3 (MCP_GENERAL_SOF | MCP_GENERAL_WAKFIL | \
+                MCP_4MHz_125kBPS_PHSEG)
+
+
+/*-----------------------*/
+/* 20 kBPS @ 4MHZ F_OSC  */
+/*-----------------------*/
+
+/* CNF1 */
+
+// SJW as defined in mcp_defs.h
+// here: SJW = 1*TQ
+#define MCP_4MHz_20kBPS_SJW (SJW1)
+
+// Prescaler = (BRP+1)*2
+// here Prescaler = 10 -> BRP=4  (20TQ)
+#define MCP_4MHz_20kBPS_BRP (4)
+
+
+/* CNF2 */
+
+// BLT-Mode defined in CNF3 (0 or BTLMODE from mcp_defs.h)
+#define MCP_4MHz_20kBPS_BLTMODE (BTLMODE)
+
+// 3 samples (SAMPLE_1X) or 1 sample (SAMPLE_1X)
+#define MCP_4MHz_20kBPS_SAM   (SAMPLE_1X)
+
+// (Phase Segment 1) PHSEG1 = PS1 - 1
+// here: PS1 calculated as 8
+#define MCP_4MHz_20kBPS_PHSEG1 ((8-1)<<3)
+
+// (Propagation Delay) PRSEG = PRSEQTQ-1
+// here PRSEQTQ = 3
+#define MCP_4MHz_20kBPS_PRSEG (3-1)
+
+/* CNF3 */
+
+// (Phase Segment 2) PHSEG2 = PS2 - 1
+// here: PS2 calculated as 8
+#define MCP_4MHz_20kBPS_PHSEG (8-1)
+
+
+#define MCP_4MHz_20kBPS_CFG1 (MCP_4MHz_20kBPS_SJW | MCP_4MHz_20kBPS_BRP)
+#define MCP_4MHz_20kBPS_CFG2 (MCP_4MHz_20kBPS_BLTMODE | MCP_4MHz_20kBPS_SAM | \
+                MCP_4MHz_20kBPS_PHSEG1 | MCP_4MHz_20kBPS_PRSEG)
+#define MCP_4MHz_20kBPS_CFG3 (MCP_GENERAL_SOF | MCP_GENERAL_WAKFIL | \
+                MCP_4MHz_20kBPS_PHSEG)