gas/doc/c-avr.texi

   1 @c Copyright (C) 2006-2014 Free Software Foundation, Inc.
   2 @c This is part of the GAS manual.
   3 @c For copying conditions, see the file as.texinfo.
   4
   5 @ifset GENERIC
   6 @page
   7 @node AVR-Dependent
   8 @chapter AVR Dependent Features
   9 @end ifset
  10
  11 @ifclear GENERIC
  12 @node Machine Dependencies
  13 @chapter AVR Dependent Features
  14 @end ifclear
  15
  16 @cindex AVR support
  17 @menu
  18 * AVR Options::              Options
  19 * AVR Syntax::               Syntax
  20 * AVR Opcodes::              Opcodes
  21 @end menu
  22
  23 @node AVR Options
  24 @section Options
  25 @cindex AVR options (none)
  26 @cindex options for AVR (none)
  27
  28 @table @code
  29
  30 @cindex @code{-mmcu=} command line option, AVR
  31 @item -mmcu=@var{mcu}
  32 Specify ATMEL AVR instruction set or MCU type.
  33
  34 Instruction set avr1 is for the minimal AVR core, not supported by the C
  35 compiler, only for assembler programs (MCU types: at90s1200,
  36 attiny11, attiny12, attiny15, attiny28).
  37
  38 Instruction set avr2 (default) is for the classic AVR core with up to
  39 8K program memory space (MCU types: at90s2313, at90s2323, at90s2333, at90s2343,
  40 attiny22, attiny26, at90s4414, at90s4433, at90s4434, at90s8515, at90c8534,
  41 at90s8535).
  42
  43 Instruction set avr25 is for the classic AVR core with up to 8K program memory
  44 space plus the MOVW instruction (MCU types: attiny13, attiny13a, attiny2313,
  45 attiny2313a, attiny24, attiny24a, attiny4313, attiny44, attiny44a, attiny84,
  46 attiny84a, attiny25, attiny45, attiny85, attiny261, attiny261a, attiny461,
  47 attiny461a, attiny861, attiny861a, attiny87, attiny43u, attiny48, attiny88,
  48 attiny828, at86rf401, ata6289, ata5272).
  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, attiny1634, at90usb82, at90usb162,
  58 atmega8u2, atmega16u2, atmega32u2, ata5505).
  59
  60 Instruction set avr4 is for the enhanced AVR core with up to 8K program
  61 memory space (MCU types: atmega48, atmega48a, atmega48pa, atmega48p, atmega8,
  62 atmega8a, atmega88, atmega88a, atmega88p, atmega88pa, atmega8515, atmega8535,
  63 atmega8hva, at90pwm1, at90pwm2, at90pwm2b, at90pwm3, at90pwm3b, at90pwm81,
  64 ata6285, ata6286).
  65
  66 Instruction set avr5 is for the enhanced AVR core with up to 128K program
  67 memory space (MCU types: at90pwm161, atmega16, atmega16a, atmega161, atmega162,
  68 atmega163, atmega164a, atmega164p, atmega164pa, atmega165, atmega165a,
  69 atmega165p, atmega165pa, atmega168, atmega168a, atmega168p, atmega168pa,
  70 atmega169, atmega169a, atmega169p, atmega169pa, atmega32, atmega323, atmega324a,
  71 atmega324p, atmega324pa, atmega325, atmega325a, atmega32, atmega32a, atmega323,
  72 atmega324a, atmega324p, atmega324pa, atmega325, atmega325a, atmega325p,
  73 atmega325p, atmega325pa, atmega3250, atmega3250a, atmega3250p, atmega3250pa,
  74 atmega328, atmega328p, atmega329, atmega329a, atmega329p, atmega329pa,
  75 atmega3290a, atmega3290p, atmega3290pa, atmega406, atmega64, atmega64a,
  76 atmega64rfr2, atmega644rfr2, atmega640, atmega644, atmega644a, atmega644p,
  77 atmega644pa, atmega645, atmega645a, atmega645p, atmega6450, atmega6450a,
  78 atmega6450p, atmega649, atmega649a, atmega649p, atmega6490, atmega6490a,
  79 atmega6490p, atmega16hva, atmega16hva2, atmega16hvb, atmega16hvbrevb,
  80 atmega32hvb, atmega32hvbrevb, atmega64hve, at90can32, at90can64, at90pwm161,
  81 at90pwm216, at90pwm316, atmega32c1, atmega64c1, atmega16m1, atmega32m1,
  82 atmega64m1, atmega16u4, atmega32u4, atmega32u6, at90usb646, at90usb647, at94k,
  83 at90scr100, ata5790, ata5795).
  84
  85 Instruction set avr51 is for the enhanced AVR core with exactly 128K program
  86 memory space (MCU types: atmega128, atmega128a, atmega1280, atmega1281,
  87 atmega1284, atmega1284p, atmega128rfa1, atmega128rfr2, atmega1284rfr2,
  88 at90can128, at90usb1286, at90usb1287, m3000).
  89
  90 Instruction set avr6 is for the enhanced AVR core with a 3-byte PC (MCU types:
  91 atmega2560, atmega2561, atmega256rfr2, atmega2564rfr2).
  92
  93 Instruction set avrxmega2 is for the XMEGA AVR core with 8K to 64K program
  94 memory space and less than 64K data space (MCU types: atxmega16a4, atxmega16a4u,
  95 atxmega16c4, atxmega16d4, atxmega16x1, atxmega32a4, atxmega32a4u, atxmega32c4,
  96 atxmega32d4, atxmega16e5, atxmega8e5, atxmega32e5, atxmega32x1).
  97
  98 Instruction set avrxmega3 is for the XMEGA AVR core with 8K to 64K program
  99 memory space and greater than 64K data space (MCU types: none).
 100
 101 Instruction set avrxmega4 is for the XMEGA AVR core with up to 64K program
 102 memory space and less than 64K data space (MCU types: atxmega64a3, atxmega64a3u,
 103 atxmega64a4u, atxmega64b1, atxmega64b3, atxmega64c3, atxmega64d3, atxmega64d4).
 104
 105 Instruction set avrxmega5 is for the XMEGA AVR core with up to 64K program
 106 memory space and greater than 64K data space (MCU types: atxmega64a1,
 107 atxmega64a1u).
 108
 109 Instruction set avrxmega6 is for the XMEGA AVR core with larger than 64K program
 110 memory space and less than 64K data space (MCU types: atxmega128a3,
 111 atxmega128a3u, atxmega128c3, atxmega128d3, atxmega128d4, atxmega192a3,
 112 atxmega192a3u, atxmega128b1, atxmega128b3, atxmega192c3, atxmega192d3,
 113 atxmega256a3, atxmega256a3u, atxmega256a3b, atxmega256a3bu, atxmega256c3,
 114 atxmega256d3, atxmega384c3, atxmega256d3).
 115
 116 Instruction set avrxmega7 is for the XMEGA AVR core with larger than 64K program
 117 memory space and greater than 64K data space (MCU types: atxmega128a1,
 118 atxmega128a1u, atxmega128a4u).
 119
 120 @cindex @code{-mall-opcodes} command line option, AVR
 121 @item -mall-opcodes
 122 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
 123
 124 @cindex @code{-mno-skip-bug} command line option, AVR
 125 @item -mno-skip-bug
 126 This option disable warnings for skipping two-word instructions.
 127
 128 @cindex @code{-mno-wrap} command line option, AVR
 129 @item -mno-wrap
 130 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
 131
 132 @end table
 133
 134
 135 @node AVR Syntax
 136 @section Syntax
 137 @menu
 138 * AVR-Chars::                Special Characters
 139 * AVR-Regs::                 Register Names
 140 * AVR-Modifiers::            Relocatable Expression Modifiers
 141 @end menu
 142
 143 @node AVR-Chars
 144 @subsection Special Characters
 145
 146 @cindex line comment character, AVR
 147 @cindex AVR line comment character
 148
 149 The presence of a @samp{;} anywhere on a line indicates the start of a
 150 comment that extends to the end of that line.
 151
 152 If a @samp{#} appears as the first character of a line, the whole line
 153 is treated as a comment, but in this case the line can also be a
 154 logical line number directive (@pxref{Comments}) or a preprocessor
 155 control command (@pxref{Preprocessing}).
 156
 157 @cindex line separator, AVR
 158 @cindex statement separator, AVR
 159 @cindex AVR line separator
 160
 161 The @samp{$} character can be used instead of a newline to separate
 162 statements.
 163
 164 @node AVR-Regs
 165 @subsection Register Names
 166
 167 @cindex AVR register names
 168 @cindex register names, AVR
 169
 170 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 171 @samp{r1}, ... @samp{r31}.
 172 Six of the 32 registers can be used as three 16-bit indirect address
 173 register pointers for Data Space addressing. One of the these address
 174 pointers can also be used as an address pointer for look up tables in
 175 Flash program memory. These added function registers are the 16-bit
 176 @samp{X}, @samp{Y} and @samp{Z} - registers.
 177
 178 @smallexample
 179 X = @r{r26:r27}
 180 Y = @r{r28:r29}
 181 Z = @r{r30:r31}
 182 @end smallexample
 183
 184 @node AVR-Modifiers
 185 @subsection Relocatable Expression Modifiers
 186
 187 @cindex AVR modifiers
 188 @cindex syntax, AVR
 189
 190 The assembler supports several modifiers when using relocatable addresses
 191 in AVR instruction operands.  The general syntax is the following:
 192
 193 @smallexample
 194 modifier(relocatable-expression)
 195 @end smallexample
 196
 197 @table @code
 198 @cindex symbol modifiers
 199
 200 @item lo8
 201
 202 This modifier allows you to use bits 0 through 7 of
 203 an address expression as 8 bit relocatable expression.
 204
 205 @item hi8
 206
 207 This modifier allows you to use bits 7 through 15 of an address expression
 208 as 8 bit relocatable expression.  This is useful with, for example, the
 209 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 210
 211 For example
 212
 213 @smallexample
 214 ldi r26, lo8(sym+10)
 215 ldi r27, hi8(sym+10)
 216 @end smallexample
 217
 218 @item hh8
 219
 220 This modifier allows you to use bits 16 through 23 of
 221 an address expression as 8 bit relocatable expression.
 222 Also, can be useful for loading 32 bit constants.
 223
 224 @item hlo8
 225
 226 Synonym of @samp{hh8}.
 227
 228 @item hhi8
 229
 230 This modifier allows you to use bits 24 through 31 of
 231 an expression as 8 bit expression. This is useful with, for example, the
 232 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 233 @samp{hhi8}, modifier.
 234
 235 For example
 236
 237 @smallexample
 238 ldi r26, lo8(285774925)
 239 ldi r27, hi8(285774925)
 240 ldi r28, hlo8(285774925)
 241 ldi r29, hhi8(285774925)
 242 ; r29,r28,r27,r26 = 285774925
 243 @end smallexample
 244
 245 @item pm_lo8
 246
 247 This modifier allows you to use bits 0 through 7 of
 248 an address expression as 8 bit relocatable expression.
 249 This modifier useful for addressing data or code from
 250 Flash/Program memory. The using of @samp{pm_lo8} similar
 251 to @samp{lo8}.
 252
 253 @item pm_hi8
 254
 255 This modifier allows you to use bits 8 through 15 of
 256 an address expression as 8 bit relocatable expression.
 257 This modifier useful for addressing data or code from
 258 Flash/Program memory.
 259
 260 @item pm_hh8
 261
 262 This modifier allows you to use bits 15 through 23 of
 263 an address expression as 8 bit relocatable expression.
 264 This modifier useful for addressing data or code from
 265 Flash/Program memory.
 266
 267 @end table
 268
 269 @node AVR Opcodes
 270 @section Opcodes
 271
 272 @cindex AVR opcode summary
 273 @cindex opcode summary, AVR
 274 @cindex mnemonics, AVR
 275 @cindex instruction summary, AVR
 276 For detailed information on the AVR machine instruction set, see
 277 @url{www.atmel.com/products/AVR}.
 278
 279 @code{@value{AS}} implements all the standard AVR opcodes.
 280 The following table summarizes the AVR opcodes, and their arguments.
 281
 282 @smallexample
 283 @i{Legend:}
 284    r   @r{any register}
 285    d   @r{`ldi' register (r16-r31)}
 286    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 287    a   @r{`fmul' register (r16-r23)}
 288    w   @r{`adiw' register (r24,r26,r28,r30)}
 289    e   @r{pointer registers (X,Y,Z)}
 290    b   @r{base pointer register and displacement ([YZ]+disp)}
 291    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 292    M   @r{immediate value from 0 to 255}
 293    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 294    s   @r{immediate value from 0 to 7}
 295    P   @r{Port address value from 0 to 63. (in, out)}
 296    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 297    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 298    i   @r{immediate value}
 299    l   @r{signed pc relative offset from -64 to 63}
 300    L   @r{signed pc relative offset from -2048 to 2047}
 301    h   @r{absolute code address (call, jmp)}
 302    S   @r{immediate value from 0 to 7 (S = s << 4)}
 303    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 304
 305 1001010010001000   clc
 306 1001010011011000   clh
 307 1001010011111000   cli
 308 1001010010101000   cln
 309 1001010011001000   cls
 310 1001010011101000   clt
 311 1001010010111000   clv
 312 1001010010011000   clz
 313 1001010000001000   sec
 314 1001010001011000   seh
 315 1001010001111000   sei
 316 1001010000101000   sen
 317 1001010001001000   ses
 318 1001010001101000   set
 319 1001010000111000   sev
 320 1001010000011000   sez
 321 100101001SSS1000   bclr    S
 322 100101000SSS1000   bset    S
 323 1001010100001001   icall
 324 1001010000001001   ijmp
 325 1001010111001000   lpm     ?
 326 1001000ddddd010+   lpm     r,z
 327 1001010111011000   elpm    ?
 328 1001000ddddd011+   elpm    r,z
 329 0000000000000000   nop
 330 1001010100001000   ret
 331 1001010100011000   reti
 332 1001010110001000   sleep
 333 1001010110011000   break
 334 1001010110101000   wdr
 335 1001010111101000   spm
 336 000111rdddddrrrr   adc     r,r
 337 000011rdddddrrrr   add     r,r
 338 001000rdddddrrrr   and     r,r
 339 000101rdddddrrrr   cp      r,r
 340 000001rdddddrrrr   cpc     r,r
 341 000100rdddddrrrr   cpse    r,r
 342 001001rdddddrrrr   eor     r,r
 343 001011rdddddrrrr   mov     r,r
 344 100111rdddddrrrr   mul     r,r
 345 001010rdddddrrrr   or      r,r
 346 000010rdddddrrrr   sbc     r,r
 347 000110rdddddrrrr   sub     r,r
 348 001001rdddddrrrr   clr     r
 349 000011rdddddrrrr   lsl     r
 350 000111rdddddrrrr   rol     r
 351 001000rdddddrrrr   tst     r
 352 0111KKKKddddKKKK   andi    d,M
 353 0111KKKKddddKKKK   cbr     d,n
 354 1110KKKKddddKKKK   ldi     d,M
 355 11101111dddd1111   ser     d
 356 0110KKKKddddKKKK   ori     d,M
 357 0110KKKKddddKKKK   sbr     d,M
 358 0011KKKKddddKKKK   cpi     d,M
 359 0100KKKKddddKKKK   sbci    d,M
 360 0101KKKKddddKKKK   subi    d,M
 361 1111110rrrrr0sss   sbrc    r,s
 362 1111111rrrrr0sss   sbrs    r,s
 363 1111100ddddd0sss   bld     r,s
 364 1111101ddddd0sss   bst     r,s
 365 10110PPdddddPPPP   in      r,P
 366 10111PPrrrrrPPPP   out     P,r
 367 10010110KKddKKKK   adiw    w,K
 368 10010111KKddKKKK   sbiw    w,K
 369 10011000pppppsss   cbi     p,s
 370 10011010pppppsss   sbi     p,s
 371 10011001pppppsss   sbic    p,s
 372 10011011pppppsss   sbis    p,s
 373 111101lllllll000   brcc    l
 374 111100lllllll000   brcs    l
 375 111100lllllll001   breq    l
 376 111101lllllll100   brge    l
 377 111101lllllll101   brhc    l
 378 111100lllllll101   brhs    l
 379 111101lllllll111   brid    l
 380 111100lllllll111   brie    l
 381 111100lllllll000   brlo    l
 382 111100lllllll100   brlt    l
 383 111100lllllll010   brmi    l
 384 111101lllllll001   brne    l
 385 111101lllllll010   brpl    l
 386 111101lllllll000   brsh    l
 387 111101lllllll110   brtc    l
 388 111100lllllll110   brts    l
 389 111101lllllll011   brvc    l
 390 111100lllllll011   brvs    l
 391 111101lllllllsss   brbc    s,l
 392 111100lllllllsss   brbs    s,l
 393 1101LLLLLLLLLLLL   rcall   L
 394 1100LLLLLLLLLLLL   rjmp    L
 395 1001010hhhhh111h   call    h
 396 1001010hhhhh110h   jmp     h
 397 1001010rrrrr0101   asr     r
 398 1001010rrrrr0000   com     r
 399 1001010rrrrr1010   dec     r
 400 1001010rrrrr0011   inc     r
 401 1001010rrrrr0110   lsr     r
 402 1001010rrrrr0001   neg     r
 403 1001000rrrrr1111   pop     r
 404 1001001rrrrr1111   push    r
 405 1001010rrrrr0111   ror     r
 406 1001010rrrrr0010   swap    r
 407 00000001ddddrrrr   movw    v,v
 408 00000010ddddrrrr   muls    d,d
 409 000000110ddd0rrr   mulsu   a,a
 410 000000110ddd1rrr   fmul    a,a
 411 000000111ddd0rrr   fmuls   a,a
 412 000000111ddd1rrr   fmulsu  a,a
 413 1001001ddddd0000   sts     i,r
 414 1001000ddddd0000   lds     r,i
 415 10o0oo0dddddbooo   ldd     r,b
 416 100!000dddddee-+   ld      r,e
 417 10o0oo1rrrrrbooo   std     b,r
 418 100!001rrrrree-+   st      e,r
 419 1001010100011001   eicall
 420 1001010000011001   eijmp
 421 @end smallexample