gas/doc/c-avr.texi

   1 @c Copyright 2006
   2 @c Free Software Foundation, Inc.
   3 @c This is part of the GAS manual.
   4 @c For copying conditions, see the file as.texinfo.
   5
   6 @ifset GENERIC
   7 @page
   8 @node AVR-Dependent
   9 @chapter AVR Dependent Features
  10 @end ifset
  11
  12 @ifclear GENERIC
  13 @node Machine Dependencies
  14 @chapter AVR Dependent Features
  15 @end ifclear
  16
  17 @cindex AVR support
  18 @menu
  19 * AVR Options::              Options
  20 * AVR Syntax::               Syntax
  21 * AVR Opcodes::              Opcodes
  22 @end menu
  23
  24 @node AVR Options
  25 @section Options
  26 @cindex AVR options (none)
  27 @cindex options for AVR (none)
  28
  29 @table @code
  30
  31 @cindex @code{-mmcu=} command line option, AVR
  32 @item -mmcu=@var{mcu}
  33 Specify ATMEL AVR instruction set or MCU type.
  34
  35 Instruction set avr1 is for the minimal AVR core, not supported by the C
  36 compiler, only for assembler programs (MCU types: at90s1200,
  37 attiny11, attiny12, attiny15, attiny28).
  38
  39 Instruction set avr2 (default) is for the classic AVR core with up to
  40 8K program memory space (MCU types: at90s2313, at90s2323, at90s2333, at90s2343,
  41 attiny22, attiny26, at90s4414, at90s4433, at90s4434, at90s8515, at90c8534,
  42 at90s8535).
  43
  44 Instruction set avr25 is for the classic AVR core with up to 8K program memory
  45 space plus the MOVW instruction (MCU types: attiny13, attiny13a, attiny2313,
  46 attiny24, attiny44, attiny84, attiny25, attiny45, attiny85, attiny261,
  47 attiny461, attiny861, attiny87, attiny43u, attiny48, attiny88, at86rf401,
  48 ata6289).
  49
  50 Instruction set avr3 is for the classic AVR core with up to 128K program
  51 memory space (MCU types: at43usb355, at76c711).
  52
  53 Instruction set avr31 is for the classic AVR core with exactly 128K program
  54 memory space (MCU types: atmega103, at43usb320).
  55
  56 Instruction set avr35 is for classic AVR core plus MOVW, CALL, and JMP
  57 instructions (MCU types: attiny167, attiny327, at90usb82, at90usb162, atmega8u2,
  58 atmega16u2, atmega32u2).
  59
  60 Instruction set avr4 is for the enhanced AVR core with up to 8K program
  61 memory space (MCU types: atmega48, atmega48p,atmega8, atmega88, atmega88p,
  62 atmega8515, atmega8535, atmega8hva, atmega4hvd, atmega8hvd, at90pwm1,
  63 at90pwm2, at90pwm2b, at90pwm3, at90pwm3b, at90pwm81, atmega8m1, atmega8c1).
  64
  65 Instruction set avr5 is for the enhanced AVR core with up to 128K program
  66 memory space (MCU types: atmega16, atmega161, atmega162, atmega163, atmega164p,
  67 atmega165, atmega165p, atmega168, atmega168p, atmega169, atmega169p, atmega16c1,
  68 atmega32, atmega323, atmega324p, atmega325, atmega325p, atmega3250, atmega3250p,
  69 atmega328p, atmega329, atmega329p, atmega3290, atmega3290p, atmega406, atmega64,
  70 atmega640, atmega644, atmega644p, atmega645, atmega6450, atmega649, atmega6490,
  71 atmega16hva, atmega16hvb, atmega32hvb, at90can32, at90can64, at90pwm216,
  72 at90pwm316, atmega32c1, atmega64c1, atmega16m1, atmega32m1, atmega64m1,
  73 atmega16u4, atmega32u4, atmega32u6, at90usb646, at90usb647, at94k, at90scr100).
  74
  75 Instruction set avr51 is for the enhanced AVR core with exactly 128K program
  76 memory space (MCU types: atmega128, atmega1280, atmega1281, atmega1284p,
  77 atmega128rfa1, at90can128, at90usb1286, at90usb1287, m3000f, m3000s, m3001b).
  78
  79 Instruction set avr6 is for the enhanced AVR core with a 3-byte PC (MCU types:
  80 atmega2560, atmega2561).
  81
  82 @cindex @code{-mall-opcodes} command line option, AVR
  83 @item -mall-opcodes
  84 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  85
  86 @cindex @code{-mno-skip-bug} command line option, AVR
  87 @item -mno-skip-bug
  88 This option disable warnings for skipping two-word instructions.
  89
  90 @cindex @code{-mno-wrap} command line option, AVR
  91 @item -mno-wrap
  92 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  93
  94 @end table
  95
  96
  97 @node AVR Syntax
  98 @section Syntax
  99 @menu
 100 * AVR-Chars::                Special Characters
 101 * AVR-Regs::                 Register Names
 102 * AVR-Modifiers::            Relocatable Expression Modifiers
 103 @end menu
 104
 105 @node AVR-Chars
 106 @subsection Special Characters
 107
 108 @cindex line comment character, AVR
 109 @cindex AVR line comment character
 110
 111 The presence of a @samp{;} on a line indicates the start of a comment
 112 that extends to the end of the current line.  If a @samp{#} appears as
 113 the first character of a line, the whole line is treated as a comment.
 114
 115 @cindex line separator, AVR
 116 @cindex statement separator, AVR
 117 @cindex AVR line separator
 118
 119 The @samp{$} character can be used instead of a newline to separate
 120 statements.
 121
 122 @node AVR-Regs
 123 @subsection Register Names
 124
 125 @cindex AVR register names
 126 @cindex register names, AVR
 127
 128 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 129 @samp{r1}, ... @samp{r31}.
 130 Six of the 32 registers can be used as three 16-bit indirect address
 131 register pointers for Data Space addressing. One of the these address
 132 pointers can also be used as an address pointer for look up tables in
 133 Flash program memory. These added function registers are the 16-bit
 134 @samp{X}, @samp{Y} and @samp{Z} - registers.
 135
 136 @smallexample
 137 X = @r{r26:r27}
 138 Y = @r{r28:r29}
 139 Z = @r{r30:r31}
 140 @end smallexample
 141
 142 @node AVR-Modifiers
 143 @subsection Relocatable Expression Modifiers
 144
 145 @cindex AVR modifiers
 146 @cindex syntax, AVR
 147
 148 The assembler supports several modifiers when using relocatable addresses
 149 in AVR instruction operands.  The general syntax is the following:
 150
 151 @smallexample
 152 modifier(relocatable-expression)
 153 @end smallexample
 154
 155 @table @code
 156 @cindex symbol modifiers
 157
 158 @item lo8
 159
 160 This modifier allows you to use bits 0 through 7 of
 161 an address expression as 8 bit relocatable expression.
 162
 163 @item hi8
 164
 165 This modifier allows you to use bits 7 through 15 of an address expression
 166 as 8 bit relocatable expression.  This is useful with, for example, the
 167 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 168
 169 For example
 170
 171 @smallexample
 172 ldi r26, lo8(sym+10)
 173 ldi r27, hi8(sym+10)
 174 @end smallexample
 175
 176 @item hh8
 177
 178 This modifier allows you to use bits 16 through 23 of
 179 an address expression as 8 bit relocatable expression.
 180 Also, can be useful for loading 32 bit constants.
 181
 182 @item hlo8
 183
 184 Synonym of @samp{hh8}.
 185
 186 @item hhi8
 187
 188 This modifier allows you to use bits 24 through 31 of
 189 an expression as 8 bit expression. This is useful with, for example, the
 190 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 191 @samp{hhi8}, modifier.
 192
 193 For example
 194
 195 @smallexample
 196 ldi r26, lo8(285774925)
 197 ldi r27, hi8(285774925)
 198 ldi r28, hlo8(285774925)
 199 ldi r29, hhi8(285774925)
 200 ; r29,r28,r27,r26 = 285774925
 201 @end smallexample
 202
 203 @item pm_lo8
 204
 205 This modifier allows you to use bits 0 through 7 of
 206 an address expression as 8 bit relocatable expression.
 207 This modifier useful for addressing data or code from
 208 Flash/Program memory. The using of @samp{pm_lo8} similar
 209 to @samp{lo8}.
 210
 211 @item pm_hi8
 212
 213 This modifier allows you to use bits 8 through 15 of
 214 an address expression as 8 bit relocatable expression.
 215 This modifier useful for addressing data or code from
 216 Flash/Program memory.
 217
 218 @item pm_hh8
 219
 220 This modifier allows you to use bits 15 through 23 of
 221 an address expression as 8 bit relocatable expression.
 222 This modifier useful for addressing data or code from
 223 Flash/Program memory.
 224
 225 @end table
 226
 227 @node AVR Opcodes
 228 @section Opcodes
 229
 230 @cindex AVR opcode summary
 231 @cindex opcode summary, AVR
 232 @cindex mnemonics, AVR
 233 @cindex instruction summary, AVR
 234 For detailed information on the AVR machine instruction set, see
 235 @url{www.atmel.com/products/AVR}.
 236
 237 @code{@value{AS}} implements all the standard AVR opcodes.
 238 The following table summarizes the AVR opcodes, and their arguments.
 239
 240 @smallexample
 241 @i{Legend:}
 242    r   @r{any register}
 243    d   @r{`ldi' register (r16-r31)}
 244    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 245    a   @r{`fmul' register (r16-r23)}
 246    w   @r{`adiw' register (r24,r26,r28,r30)}
 247    e   @r{pointer registers (X,Y,Z)}
 248    b   @r{base pointer register and displacement ([YZ]+disp)}
 249    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 250    M   @r{immediate value from 0 to 255}
 251    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 252    s   @r{immediate value from 0 to 7}
 253    P   @r{Port address value from 0 to 63. (in, out)}
 254    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 255    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 256    i   @r{immediate value}
 257    l   @r{signed pc relative offset from -64 to 63}
 258    L   @r{signed pc relative offset from -2048 to 2047}
 259    h   @r{absolute code address (call, jmp)}
 260    S   @r{immediate value from 0 to 7 (S = s << 4)}
 261    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 262
 263 1001010010001000   clc
 264 1001010011011000   clh
 265 1001010011111000   cli
 266 1001010010101000   cln
 267 1001010011001000   cls
 268 1001010011101000   clt
 269 1001010010111000   clv
 270 1001010010011000   clz
 271 1001010000001000   sec
 272 1001010001011000   seh
 273 1001010001111000   sei
 274 1001010000101000   sen
 275 1001010001001000   ses
 276 1001010001101000   set
 277 1001010000111000   sev
 278 1001010000011000   sez
 279 100101001SSS1000   bclr    S
 280 100101000SSS1000   bset    S
 281 1001010100001001   icall
 282 1001010000001001   ijmp
 283 1001010111001000   lpm     ?
 284 1001000ddddd010+   lpm     r,z
 285 1001010111011000   elpm    ?
 286 1001000ddddd011+   elpm    r,z
 287 0000000000000000   nop
 288 1001010100001000   ret
 289 1001010100011000   reti
 290 1001010110001000   sleep
 291 1001010110011000   break
 292 1001010110101000   wdr
 293 1001010111101000   spm
 294 000111rdddddrrrr   adc     r,r
 295 000011rdddddrrrr   add     r,r
 296 001000rdddddrrrr   and     r,r
 297 000101rdddddrrrr   cp      r,r
 298 000001rdddddrrrr   cpc     r,r
 299 000100rdddddrrrr   cpse    r,r
 300 001001rdddddrrrr   eor     r,r
 301 001011rdddddrrrr   mov     r,r
 302 100111rdddddrrrr   mul     r,r
 303 001010rdddddrrrr   or      r,r
 304 000010rdddddrrrr   sbc     r,r
 305 000110rdddddrrrr   sub     r,r
 306 001001rdddddrrrr   clr     r
 307 000011rdddddrrrr   lsl     r
 308 000111rdddddrrrr   rol     r
 309 001000rdddddrrrr   tst     r
 310 0111KKKKddddKKKK   andi    d,M
 311 0111KKKKddddKKKK   cbr     d,n
 312 1110KKKKddddKKKK   ldi     d,M
 313 11101111dddd1111   ser     d
 314 0110KKKKddddKKKK   ori     d,M
 315 0110KKKKddddKKKK   sbr     d,M
 316 0011KKKKddddKKKK   cpi     d,M
 317 0100KKKKddddKKKK   sbci    d,M
 318 0101KKKKddddKKKK   subi    d,M
 319 1111110rrrrr0sss   sbrc    r,s
 320 1111111rrrrr0sss   sbrs    r,s
 321 1111100ddddd0sss   bld     r,s
 322 1111101ddddd0sss   bst     r,s
 323 10110PPdddddPPPP   in      r,P
 324 10111PPrrrrrPPPP   out     P,r
 325 10010110KKddKKKK   adiw    w,K
 326 10010111KKddKKKK   sbiw    w,K
 327 10011000pppppsss   cbi     p,s
 328 10011010pppppsss   sbi     p,s
 329 10011001pppppsss   sbic    p,s
 330 10011011pppppsss   sbis    p,s
 331 111101lllllll000   brcc    l
 332 111100lllllll000   brcs    l
 333 111100lllllll001   breq    l
 334 111101lllllll100   brge    l
 335 111101lllllll101   brhc    l
 336 111100lllllll101   brhs    l
 337 111101lllllll111   brid    l
 338 111100lllllll111   brie    l
 339 111100lllllll000   brlo    l
 340 111100lllllll100   brlt    l
 341 111100lllllll010   brmi    l
 342 111101lllllll001   brne    l
 343 111101lllllll010   brpl    l
 344 111101lllllll000   brsh    l
 345 111101lllllll110   brtc    l
 346 111100lllllll110   brts    l
 347 111101lllllll011   brvc    l
 348 111100lllllll011   brvs    l
 349 111101lllllllsss   brbc    s,l
 350 111100lllllllsss   brbs    s,l
 351 1101LLLLLLLLLLLL   rcall   L
 352 1100LLLLLLLLLLLL   rjmp    L
 353 1001010hhhhh111h   call    h
 354 1001010hhhhh110h   jmp     h
 355 1001010rrrrr0101   asr     r
 356 1001010rrrrr0000   com     r
 357 1001010rrrrr1010   dec     r
 358 1001010rrrrr0011   inc     r
 359 1001010rrrrr0110   lsr     r
 360 1001010rrrrr0001   neg     r
 361 1001000rrrrr1111   pop     r
 362 1001001rrrrr1111   push    r
 363 1001010rrrrr0111   ror     r
 364 1001010rrrrr0010   swap    r
 365 00000001ddddrrrr   movw    v,v
 366 00000010ddddrrrr   muls    d,d
 367 000000110ddd0rrr   mulsu   a,a
 368 000000110ddd1rrr   fmul    a,a
 369 000000111ddd0rrr   fmuls   a,a
 370 000000111ddd1rrr   fmulsu  a,a
 371 1001001ddddd0000   sts     i,r
 372 1001000ddddd0000   lds     r,i
 373 10o0oo0dddddbooo   ldd     r,b
 374 100!000dddddee-+   ld      r,e
 375 10o0oo1rrrrrbooo   std     b,r
 376 100!001rrrrree-+   st      e,r
 377 1001010100011001   eicall
 378 1001010000011001   eijmp
 379 @end smallexample