/* * SYNCM 7 6 5 4 3 2 1 0 * Name RSVD RSVD LVDS WIDE ALTPERD PERIOD2 PERIOD1 PERIOD0 * Default 0 0 0 0 0 0 0 0 * * Bit Name Definition * 07-06 0 RSVD Reversed. Always read 0 * 05 0 LVDS Reversed. Always read 0 * 04 0 WIDE/WSCSI Enable wide (16-bits) SCSI transfer. * 03 0 ALTPERD/ALTPD Alternate (Sync./Period) mode. * * @@ When this bit is set, * the synchronous period bits 2:0 * in the Synchronous Mode register * are used to transfer data * at the Fast-20 rate. * @@ When this bit is reset, * the synchronous period bits 2:0 * in the Synchronous Mode Register * are used to transfer data * at the Fast-40 rate. * * 02-00 0 PERIOD[2:0]/SXPD[02:00] Synchronous SCSI Transfer Rate. * These 3 bits specify * the Synchronous SCSI Transfer Rate * for Fast-20 and Fast-10. * These bits are also reset * by a SCSI Bus reset. * * For Fast-10 bit ALTPD = 0 and LVDS = 0 * and bit2,bit1,bit0 is defined as follows : * * 000 100ns, 10.0 Mbytes/s * 001 150ns, 6.6 Mbytes/s * 010 200ns, 5.0 Mbytes/s * 011 250ns, 4.0 Mbytes/s * 100 300ns, 3.3 Mbytes/s * 101 350ns, 2.8 Mbytes/s * 110 400ns, 2.5 Mbytes/s * 111 450ns, 2.2 Mbytes/s * * For Fast-20 bit ALTPD = 1 and LVDS = 0 * and bit2,bit1,bit0 is defined as follows : * * 000 50ns, 20.0 Mbytes/s * 001 75ns, 13.3 Mbytes/s * 010 100ns, 10.0 Mbytes/s * 011 125ns, 8.0 Mbytes/s * 100 150ns, 6.6 Mbytes/s * 101 175ns, 5.7 Mbytes/s * 110 200ns, 5.0 Mbytes/s * 111 250ns, 4.0 Mbytes/s * * For Fast-40 bit ALTPD = 0 and LVDS = 1 * and bit2,bit1,bit0 is defined as follows : * * 000 25ns, 40.0 Mbytes/s * 001 50ns, 20.0 Mbytes/s * 010 75ns, 13.3 Mbytes/s * 011 100ns, 10.0 Mbytes/s * 100 125ns, 8.0 Mbytes/s * 101 150ns, 6.6 Mbytes/s * 110 175ns, 5.7 Mbytes/s * 111 200ns, 5.0 Mbytes/s */