simple_cdrom_controller.a51

8051控制CDROM驱动

; running self diagonistics..
; nb/ this is the first ATA command we send
;
  lcall lprint
  db    'Passed ATA self diagnositics?..',0

  mov   a,#90h
  acall set_cmd_register

  acall bsy_wait
  acall get_error_register
  jb    acc.0,init_device_c1
  acall print_no
  sjmp  $
init_device_c1:
  acall print_yes
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; ATAPI identify packet device
;
; this ATA/ATAPI command is mandatory for CDROM (and like) devices, as it
; will enable the DRDY flag. without this command, we won't be able to
; issue any commands (ATA or packet).
;
; nb/ older ATA standards, DRDY goes high immediately after BSY goes low
; during reset. .. not so for CDROM devices ;)
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
skip_device_fields:
  acall get_data
  djnz  r7,skip_device_fields
  ret

print_device_ansi:
  acall get_data
  xch   a,b
  lcall writechar
  mov   a,b
  lcall writechar
  djnz  r7,print_device_ansi
  ret

identify_packet_device:
  lcall lprint
  db    'Identifying ATAPI device:',13,10,0

;identify device cmd
;
  mov   a,#2h                 ;set byte count registers
  acall set_cyl_high_register ;maximum transfer length = 0200h
  clr   a                     ;nb/ on the few devices i've tested, this
  acall set_cyl_low_register  ;cmd automatically sets these registers.
                              ;but i'll set it for consistency ;)
  mov   a,#0a1h
  acall set_cmd_register
  acall wait_irq

; get general config word
;
  acall get_data
  jnb   b.7,identify_packet_device_c0
  jb    b.6,identify_packet_device_c0
  lcall lprint
  db    9,'Unit is an ATAPI device',13,10,0
identify_packet_device_c0:

  jnb   acc.7,identify_packet_device_c1
  lcall lprint
  db    9,'Unit has removable media',13,10,0
identify_packet_device_c1:

  lcall lprint
  db    9,'packet size (words): ',0
  clr   a
  jb    acc.0,identify_packet_device_c2
  jb    acc.1,identify_packet_device_c2
  mov   a,#6
identify_packet_device_c2:

  jb    acc.0,identify_packet_device_c3
  jnb   acc.1,identify_packet_device_c3
  mov   a,#8
identify_packet_device_c3:
  mov   packet_size,a
  lcall prhex
  lcall prcrlf

  lcall lprint
  db    9,'type:',9,0
  mov   a,b
  anl   a,#0fh
  lcall prhex
  lcall prcrlf

; skip next 9 words
;
  mov   r7,#9
  acall skip_device_fields

; get serial number
;
  lcall lprint
  db    9,'serial:',9,0
  mov   r7,#10
  acall print_device_ansi
  lcall prcrlf

; skip next 3 words
;
  mov   r7,#3
  acall skip_device_fields

; get firmware revision
;
  lcall lprint
  db    9,'rev:',9,0
  mov   r7,#4
  acall print_device_ansi
  lcall prcrlf

; get model number
;
  lcall lprint
  db    9,'model:',9,0
  mov   r7,#20
  acall print_device_ansi
  lcall prcrlf

; skip next 33 words
;
  mov   r7,#33
  acall skip_device_fields

; get major version
;
  lcall lprint
  db    9,'major:',9,0
  acall get_data  
  xch   a,b
  lcall prhex
  mov   a,b
  lcall prhex
  lcall prcrlf

; get major version
;
  lcall lprint
  db    9,'minor:',9,0
  acall get_data  
  xch   a,b
  lcall prhex
  mov   a,b
  lcall prhex
  lcall prcrlf

; skip next 46 words
;
  mov   r7,#46
  acall skip_device_fields

; get security word
;
  lcall lprint
  db    9,'secure:',9,0
  acall get_data
  xch   a,b
  lcall prhex
  mov   a,b
  lcall prhex
  lcall prcrlf

  acall skip_rest_of_packet

  acall bsy_drdy_wait
  lcall lprint
  db    'ATAPI device now has READY status.',13,10,0
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
do_packet_cmd:

; clr packet table
;
  mov   r0,#packet_tab
  mov   r7,#16
init_pck_l:
  mov   @r0,#0
  inc   r0
  djnz  r7,init_pck_l

; send packet command
;
  acall ndrq_wait
  mov   a,#0a0h
  acall set_cmd_register
  ret


send_packet:
  acall drq_wait

  mov   r0,#packet_tab
  mov   r7,#packet_size
send_packet_l:
  mov   a,@r0
  inc   r0
  push  acc
  mov   a,@r0
  inc   r0
  mov   b,a
  pop   acc
  acall set_data
  djnz  r7,send_packet_l

  acall wait_irq
  acall get_status_register
  ret

print_packet_error:
  lcall lprint
  db    '...Failed: ',0
  acall get_error_register
  lcall prhex
  lcall prcrlf
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; test unit ready ATAPI command
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
test_unit_ready_cmd:
  acall do_packet_cmd
  acall send_packet
  jnb   STATUS_REG_ERR,test_unit_ready_d
  clr   c
  ret
test_unit_ready_d:
  setb  c
  ret

wait_for_ready_state:
  lcall lprint
  db    'Waiting for Unit READY state (insert CD. if not inserted).',13,10,0

  mov   r2,#2
wait_for_ready_state_l:
  mov   r5,#1
  acall delay
  acall test_unit_ready_cmd
  jnc   wait_for_ready_state_l
  dec   r2
  cjne  r2,#0,wait_for_ready_state_l
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Table of Contents command
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
read_toc_cmd:
  lcall lprint
  db    'Read TOC cmd..',13,10,0

  mov   a,#0ffh               ;set byte counter register
  acall set_cyl_low_register  ;(set it to full on.. it doesn't matter coz
  acall set_cyl_high_register ;DRQ controls the feed)

  acall do_packet_cmd
  mov   packet_cmd,#43h
  mov   packet_1,#00000010b   ;MSF=1
  mov   packet_7,#0ffh        ;allocation length
  mov   packet_8,#0ffh        ;(again, set it to full on)
  acall send_packet
  jb    STATUS_REG_ERR,read_toc_cmd_e
  jb    STATUS_REG_DRQ,read_toc_cmd_r
  setb  c
  ret
read_toc_cmd_e:
  acall print_packet_error
  clr   c
  ret

; read header
;
read_toc_cmd_r:
  acall get_data       ;data length

  acall get_data       ;get track limits
  mov   start_track,a

  lcall lprint
  db    9,'Start Trk:',9,0
  mov   a,start_track
  lcall prhex
  lcall prcrlf

  lcall lprint
  db    9,'End Trk:',9,0
  mov   a,b
  lcall prhex
  lcall prcrlf

; read track descriptors
;
  lcall lprint
  db    9,'Tracks-',13,10
  db    9,9,'ADR/Ctl',9,'Trk',9,'MSF',13,10
  db    0
read_toc_cmd_l2:
  lcall lprint
  db    9,9,0

  acall get_data   ;get ADR and control fields
  mov   a,b
  lcall prhex
  mov   a,#9
  lcall writechar

  acall get_data   ;get track number
  mov   tmp0,a
  lcall prhex
  mov   a,#9
  lcall writechar

  acall get_MSF_field

; if start track, then record start position
;
  mov   a,tmp0
  cjne  a,start_track,read_toc_cmd_i0
  mov   start_M,tmp1
  mov   start_S,tmp2
  mov   start_F,tmp3
read_toc_cmd_i0:

;if the last track, then record as end position
;
  cjne  a,#0aah,read_toc_cmd_i1
  mov   end_M,tmp1
  mov   end_S,tmp2
  mov   end_F,tmp3
read_toc_cmd_i1:

  acall bsy_wait
  jb    STATUS_REG_DRQ,read_toc_cmd_l2
  setb  c
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; play MSF cd cmd
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
play_entire_cd_cmd:
  lcall lprint
  db    'Play Entire CD (Play Audio MSF cmd)..',13,10,0

  acall do_packet_cmd
  mov   packet_cmd,#47h
  mov   packet_3,start_M
  mov   packet_4,start_S
  mov   packet_5,start_F
  mov   packet_6,end_M
  mov   packet_7,end_S
  mov   packet_8,end_F
  acall send_packet
  jnb   STATUS_REG_ERR,play_audio_cmd_d
  acall print_packet_error
  clr   c
  ret
play_audio_cmd_d:
  setb  c
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; read sub channel cmd
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
read_subchan_cmd:
  lcall lprint
  db    'Read Sub-Channel cmd..',13,10,0

  mov   a,#0ffh               ;set byte counter register
  acall set_cyl_low_register  ;(set it to full on.. it doesn't matter coz
  acall set_cyl_high_register ;DRQ controls the feed)

  acall do_packet_cmd
  mov   packet_cmd,#42h
  mov   packet_1,#00000010b  ;MSF=1
  mov   packet_2,#01000000b  ;SubQ=1
  mov   packet_3,#01h        ;format=01  (current position)
  mov   packet_7,#0ffh       ;allocation length
  mov   packet_8,#0ffh       ;(set it to full on)
  acall send_packet
  jb    STATUS_REG_ERR,read_subchan_cmd_e
  jb    STATUS_REG_DRQ,read_subchan_cmd_r
  ret
read_subchan_cmd_e:
  acall print_packet_error
  ret

;read sub-channel header
;
read_subchan_cmd_r:
  acall get_data   ;get audio status
  lcall lprint
  db    9,'Audio Status:',9,0
  mov   a,b
  lcall prhex
  lcall prcrlf

  acall get_data   ;sub channel data length (will be zero).. ignore
  acall get_data   ;format code, ADR, cntl (ignore)

  lcall lprint     ;track number, index number
  db    9,'Track number:',9,0
  acall get_data
  lcall prhex
  lcall prcrlf

  lcall lprint     ;absolete CDROM address
  db    9,'Abs address:',9,0
  acall get_MSF_field

  lcall lprint     ;relative CDROM address
  db    9,'Rel address:',9,0
  acall get_MSF_field

  acall skip_rest_of_packet
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; stop/play command
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
stop_play_cmd:
  lcall lprint
  db    'Stop play cmd..',13,10,0

  acall do_packet_cmd
  mov   packet_cmd,#4eh
  acall send_packet
  jnb   STATUS_REG_ERR,stop_play_cmd_d
  acall print_packet_error
stop_play_cmd_d:
  ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; program entry point
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
start:
  mov   sp,#07fh  ;set stack position

  lcall prcrlf
  lcall lprint
  db    'A Simple 8051 based ATAPI CDROM audio controller version 0,',13,10
  db    'Copyright (C) 2000 Jason Nunn <[e-mail]>',13,10,
  db    13,10
  db    'This software comes under the GNU public license agreement.',13,10
  db    'See the COPYING file in this distribution.',13,10
  db    13,10
  db    'If you use this code (or parts) of it, then please credit me.',13,10
  db    0

  acall init_ata_device
  acall identify_packet_device

  lcall lprint
  db    'Settling delay..',13,10,0
  mov   r5,#1
  acall delay

main_loop:
  acall wait_for_ready_state

  acall read_toc_cmd
  jnc   main_loop

  acall play_entire_cd_cmd
  jnc   main_loop

  lcall lprint
  db    'Playing..',13,10,0
play_loop:
  acall read_subchan_cmd

  lcall lprint
  db    'Hit "q" to stop play..',13,10,0

  mov   r5,#1
  acall delay

  mov   a,s1con            ;read character
  jnb   acc.0,play_loop
  anl   s1con,#0feh
  mov   a,s1buf
  anl   a,#7fh
  cjne  a,#'q',play_loop

  acall stop_play_cmd

  lcall lprint
  db    'Play has been stopped.. Program ended.',13,10,0
  sjmp  $
end