freebsd-src/sys/isa/ic/nec765.h
Tor Egge d66c374f58 Enable the FIFO on enhanced floppy controllers. This reduces the
number of dma overruns/underruns for systems under heavy dma load.
As a side effect, broken enhanced floppy controllers that sometimes
don't detect dma overruns/underruns will give less errors.

Reviewed by:	j@uriah.heep.sax.de (J Wunsch)
1997-09-17 20:16:17 +00:00

143 lines
6.3 KiB
C

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)nec765.h 7.1 (Berkeley) 5/9/91
* $Id: nec765.h,v 1.6 1997/02/22 09:38:04 peter Exp $
*/
/*
* Nec 765 floppy disc controller definitions
*/
/* Main status register */
#define NE7_DAB 0x01 /* Diskette drive A is seeking, thus busy */
#define NE7_DBB 0x02 /* Diskette drive B is seeking, thus busy */
#define NE7_CB 0x10 /* Diskette Controller Busy */
#define NE7_NDM 0x20 /* Diskette Controller in Non Dma Mode */
#define NE7_DIO 0x40 /* Diskette Controller Data register I/O */
#define NE7_RQM 0x80 /* Diskette Controller ReQuest for Master */
/* Status register ST0 */
#define NE7_ST0BITS "\020\010invld\007abnrml\006seek_cmplt\005equ_chck\004drive_notrdy\003top_head"
#define NE7_ST0_IC 0xc0 /* interrupt completion code */
#define NE7_ST0_IC_RC 0xc0 /* terminated due to ready changed, n/a */
#define NE7_ST0_IC_IV 0x80 /* invalid command; must reset FDC */
#define NE7_ST0_IC_AT 0x40 /* abnormal termination, check error stat */
#define NE7_ST0_IC_NT 0x00 /* normal termination */
#define NE7_ST0_SE 0x20 /* seek end */
#define NE7_ST0_EC 0x10 /* equipment check, recalibrated but no trk0 */
#define NE7_ST0_NR 0x08 /* not ready (n/a) */
#define NE7_ST0_HD 0x04 /* upper head selected */
#define NE7_ST0_DR 0x03 /* drive code */
/* Status register ST1 */
#define NE7_ST1BITS "\020\010end_of_cyl\006bad_crc\005data_overrun\003sec_not_fnd\002write_protect\001no_am"
#define NE7_ST1_EN 0x80 /* end of cylinder, access past last record */
#define NE7_ST1_DE 0x20 /* data error, CRC fail in ID or data */
#define NE7_ST1_OR 0x10 /* DMA overrun, DMA failed to do i/o quickly */
#define NE7_ST1_ND 0x04 /* no data, sector not found or CRC in ID f. */
#define NE7_ST1_NW 0x02 /* not writeable, attempt to violate WP */
#define NE7_ST1_MA 0x01 /* missing address mark (in ID or data field)*/
/* Status register ST2 */
#define NE7_ST2BITS "\020\007ctrl_mrk\006bad_crc\005wrong_cyl\004scn_eq\003scn_not_fnd\002bad_cyl\001no_dam"
#define NE7_ST2_CM 0x40 /* control mark; found deleted data */
#define NE7_ST2_DD 0x20 /* data error in data field, CRC fail */
#define NE7_ST2_WC 0x10 /* wrong cylinder, ID field mismatches cmd */
#define NE7_ST2_SH 0x08 /* scan equal hit */
#define NE7_ST2_SN 0x04 /* scan not satisfied */
#define NE7_ST2_BC 0x02 /* bad cylinder, cylinder marked 0xff */
#define NE7_ST2_MD 0x01 /* missing address mark in data field */
/* Status register ST3 */
#define NE7_ST3BITS "\020\010fault\007write_protect\006drdy\005tk0\004two_side\003side_sel\002"
#define NE7_ST3_FT 0x80 /* fault; PC: n/a */
#define NE7_ST3_WP 0x40 /* write protected */
#define NE7_ST3_RD 0x20 /* ready; PC: always true */
#define NE7_ST3_T0 0x10 /* track 0 */
#define NE7_ST3_TS 0x08 /* two-sided; PC: n/a */
#define NE7_ST3_HD 0x04 /* upper head select */
#define NE7_ST3_US 0x03 /* unit select */
/* Commands */
/*
* the top three bits -- where appropriate -- are set as follows:
*
* 0x80 - MT multi-track; allow both sides to be handled in single cmd
* 0x40 - MFM modified frequency modulation; use MFM encoding
* 0x20 - SK skip; skip sectors marked as "deleted"
*/
#define NE7CMD_READTRK 0x42 /* read whole track */
#define NE7CMD_SPECIFY 3 /* specify drive parameters - requires unit
parameters byte */
#define NE7CMD_SENSED 4 /* sense drive - requires unit select byte */
#define NE7CMD_WRITE 0xc5 /* write - requires eight additional bytes */
#define NE7CMD_READ 0xe6 /* read - requires eight additional bytes */
#define NE7CMD_RECAL 7 /* recalibrate drive - requires
unit select byte */
#define NE7CMD_SENSEI 8 /* sense controller interrupt status */
#define NE7CMD_WRITEDEL 0xc9 /* write deleted data */
#define NE7CMD_READID 0x4a /* read ID field */
#define NE7CMD_READDEL 0xec /* read deleted data */
#define NE7CMD_FORMAT 0x4d /* format - requires five additional bytes */
#define NE7CMD_SEEK 0x0f /* seek drive - requires unit select byte
and new cyl byte */
#define NE7CMD_SCNEQU 0xf1 /* scan equal */
#define NE7CMD_SCNLE 0xf9 /* scan less or equal */
#define NE7CMD_SCNGE 0xfd /* scan greater or equal */
/*
* Enhanced controller commands:
*/
#define NE7CMD_VERSION 0x10 /* version (ok for all controllers) */
#define I8207X_CONFIGURE 0x13 /* configure enhanced features */
/*
* "specify" definitions
*
* acronyms (times are relative to a FDC clock of 8 MHz):
* srt - step rate; PC usually 3 ms
* hut - head unload time; PC usually maximum of 240 ms
* hlt - head load time; PC usually minimum of 2 ms
* nd - no DMA flag; PC usually not set (0)
*/
#define NE7_SPEC_1(srt, hut) (((16 - (srt)) << 4) | (((hut) / 16)))
#define NE7_SPEC_2(hlt, nd) (((hlt) & 0xFE) | ((nd) & 1))