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 @cindex @code{-mrmw} command line option, AVR
 133 @item -mrmw
 134 Accept Read-Modify-Write (@code{XCH,LAC,LAS,LAT}) instructions.
 135
 136 @end table
 137
 138
 139 @node AVR Syntax
 140 @section Syntax
 141 @menu
 142 * AVR-Chars::                Special Characters
 143 * AVR-Regs::                 Register Names
 144 * AVR-Modifiers::            Relocatable Expression Modifiers
 145 @end menu
 146
 147 @node AVR-Chars
 148 @subsection Special Characters
 149
 150 @cindex line comment character, AVR
 151 @cindex AVR line comment character
 152
 153 The presence of a @samp{;} anywhere on a line indicates the start of a
 154 comment that extends to the end of that line.
 155
 156 If a @samp{#} appears as the first character of a line, the whole line
 157 is treated as a comment, but in this case the line can also be a
 158 logical line number directive (@pxref{Comments}) or a preprocessor
 159 control command (@pxref{Preprocessing}).
 160
 161 @cindex line separator, AVR
 162 @cindex statement separator, AVR
 163 @cindex AVR line separator
 164
 165 The @samp{$} character can be used instead of a newline to separate
 166 statements.
 167
 168 @node AVR-Regs
 169 @subsection Register Names
 170
 171 @cindex AVR register names
 172 @cindex register names, AVR
 173
 174 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 175 @samp{r1}, ... @samp{r31}.
 176 Six of the 32 registers can be used as three 16-bit indirect address
 177 register pointers for Data Space addressing. One of the these address
 178 pointers can also be used as an address pointer for look up tables in
 179 Flash program memory. These added function registers are the 16-bit
 180 @samp{X}, @samp{Y} and @samp{Z} - registers.
 181
 182 @smallexample
 183 X = @r{r26:r27}
 184 Y = @r{r28:r29}
 185 Z = @r{r30:r31}
 186 @end smallexample
 187
 188 @node AVR-Modifiers
 189 @subsection Relocatable Expression Modifiers
 190
 191 @cindex AVR modifiers
 192 @cindex syntax, AVR
 193
 194 The assembler supports several modifiers when using relocatable addresses
 195 in AVR instruction operands.  The general syntax is the following:
 196
 197 @smallexample
 198 modifier(relocatable-expression)
 199 @end smallexample
 200
 201 @table @code
 202 @cindex symbol modifiers
 203
 204 @item lo8
 205
 206 This modifier allows you to use bits 0 through 7 of
 207 an address expression as 8 bit relocatable expression.
 208
 209 @item hi8
 210
 211 This modifier allows you to use bits 7 through 15 of an address expression
 212 as 8 bit relocatable expression.  This is useful with, for example, the
 213 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 214
 215 For example
 216
 217 @smallexample
 218 ldi r26, lo8(sym+10)
 219 ldi r27, hi8(sym+10)
 220 @end smallexample
 221
 222 @item hh8
 223
 224 This modifier allows you to use bits 16 through 23 of
 225 an address expression as 8 bit relocatable expression.
 226 Also, can be useful for loading 32 bit constants.
 227
 228 @item hlo8
 229
 230 Synonym of @samp{hh8}.
 231
 232 @item hhi8
 233
 234 This modifier allows you to use bits 24 through 31 of
 235 an expression as 8 bit expression. This is useful with, for example, the
 236 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 237 @samp{hhi8}, modifier.
 238
 239 For example
 240
 241 @smallexample
 242 ldi r26, lo8(285774925)
 243 ldi r27, hi8(285774925)
 244 ldi r28, hlo8(285774925)
 245 ldi r29, hhi8(285774925)
 246 ; r29,r28,r27,r26 = 285774925
 247 @end smallexample
 248
 249 @item pm_lo8
 250
 251 This modifier allows you to use bits 0 through 7 of
 252 an address expression as 8 bit relocatable expression.
 253 This modifier useful for addressing data or code from
 254 Flash/Program memory. The using of @samp{pm_lo8} similar
 255 to @samp{lo8}.
 256
 257 @item pm_hi8
 258
 259 This modifier allows you to use bits 8 through 15 of
 260 an address expression as 8 bit relocatable expression.
 261 This modifier useful for addressing data or code from
 262 Flash/Program memory.
 263
 264 @item pm_hh8
 265
 266 This modifier allows you to use bits 15 through 23 of
 267 an address expression as 8 bit relocatable expression.
 268 This modifier useful for addressing data or code from
 269 Flash/Program memory.
 270
 271 @end table
 272
 273 @node AVR Opcodes
 274 @section Opcodes
 275
 276 @cindex AVR opcode summary
 277 @cindex opcode summary, AVR
 278 @cindex mnemonics, AVR
 279 @cindex instruction summary, AVR
 280 For detailed information on the AVR machine instruction set, see
 281 @url{www.atmel.com/products/AVR}.
 282
 283 @code{@value{AS}} implements all the standard AVR opcodes.
 284 The following table summarizes the AVR opcodes, and their arguments.
 285
 286 @smallexample
 287 @i{Legend:}
 288    r   @r{any register}
 289    d   @r{`ldi' register (r16-r31)}
 290    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 291    a   @r{`fmul' register (r16-r23)}
 292    w   @r{`adiw' register (r24,r26,r28,r30)}
 293    e   @r{pointer registers (X,Y,Z)}
 294    b   @r{base pointer register and displacement ([YZ]+disp)}
 295    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 296    M   @r{immediate value from 0 to 255}
 297    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 298    s   @r{immediate value from 0 to 7}
 299    P   @r{Port address value from 0 to 63. (in, out)}
 300    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 301    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 302    i   @r{immediate value}
 303    l   @r{signed pc relative offset from -64 to 63}
 304    L   @r{signed pc relative offset from -2048 to 2047}
 305    h   @r{absolute code address (call, jmp)}
 306    S   @r{immediate value from 0 to 7 (S = s << 4)}
 307    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 308
 309 1001010010001000   clc
 310 1001010011011000   clh
 311 1001010011111000   cli
 312 1001010010101000   cln
 313 1001010011001000   cls
 314 1001010011101000   clt
 315 1001010010111000   clv
 316 1001010010011000   clz
 317 1001010000001000   sec
 318 1001010001011000   seh
 319 1001010001111000   sei
 320 1001010000101000   sen
 321 1001010001001000   ses
 322 1001010001101000   set
 323 1001010000111000   sev
 324 1001010000011000   sez
 325 100101001SSS1000   bclr    S
 326 100101000SSS1000   bset    S
 327 1001010100001001   icall
 328 1001010000001001   ijmp
 329 1001010111001000   lpm     ?
 330 1001000ddddd010+   lpm     r,z
 331 1001010111011000   elpm    ?
 332 1001000ddddd011+   elpm    r,z
 333 0000000000000000   nop
 334 1001010100001000   ret
 335 1001010100011000   reti
 336 1001010110001000   sleep
 337 1001010110011000   break
 338 1001010110101000   wdr
 339 1001010111101000   spm
 340 000111rdddddrrrr   adc     r,r
 341 000011rdddddrrrr   add     r,r
 342 001000rdddddrrrr   and     r,r
 343 000101rdddddrrrr   cp      r,r
 344 000001rdddddrrrr   cpc     r,r
 345 000100rdddddrrrr   cpse    r,r
 346 001001rdddddrrrr   eor     r,r
 347 001011rdddddrrrr   mov     r,r
 348 100111rdddddrrrr   mul     r,r
 349 001010rdddddrrrr   or      r,r
 350 000010rdddddrrrr   sbc     r,r
 351 000110rdddddrrrr   sub     r,r
 352 001001rdddddrrrr   clr     r
 353 000011rdddddrrrr   lsl     r
 354 000111rdddddrrrr   rol     r
 355 001000rdddddrrrr   tst     r
 356 0111KKKKddddKKKK   andi    d,M
 357 0111KKKKddddKKKK   cbr     d,n
 358 1110KKKKddddKKKK   ldi     d,M
 359 11101111dddd1111   ser     d
 360 0110KKKKddddKKKK   ori     d,M
 361 0110KKKKddddKKKK   sbr     d,M
 362 0011KKKKddddKKKK   cpi     d,M
 363 0100KKKKddddKKKK   sbci    d,M
 364 0101KKKKddddKKKK   subi    d,M
 365 1111110rrrrr0sss   sbrc    r,s
 366 1111111rrrrr0sss   sbrs    r,s
 367 1111100ddddd0sss   bld     r,s
 368 1111101ddddd0sss   bst     r,s
 369 10110PPdddddPPPP   in      r,P
 370 10111PPrrrrrPPPP   out     P,r
 371 10010110KKddKKKK   adiw    w,K
 372 10010111KKddKKKK   sbiw    w,K
 373 10011000pppppsss   cbi     p,s
 374 10011010pppppsss   sbi     p,s
 375 10011001pppppsss   sbic    p,s
 376 10011011pppppsss   sbis    p,s
 377 111101lllllll000   brcc    l
 378 111100lllllll000   brcs    l
 379 111100lllllll001   breq    l
 380 111101lllllll100   brge    l
 381 111101lllllll101   brhc    l
 382 111100lllllll101   brhs    l
 383 111101lllllll111   brid    l
 384 111100lllllll111   brie    l
 385 111100lllllll000   brlo    l
 386 111100lllllll100   brlt    l
 387 111100lllllll010   brmi    l
 388 111101lllllll001   brne    l
 389 111101lllllll010   brpl    l
 390 111101lllllll000   brsh    l
 391 111101lllllll110   brtc    l
 392 111100lllllll110   brts    l
 393 111101lllllll011   brvc    l
 394 111100lllllll011   brvs    l
 395 111101lllllllsss   brbc    s,l
 396 111100lllllllsss   brbs    s,l
 397 1101LLLLLLLLLLLL   rcall   L
 398 1100LLLLLLLLLLLL   rjmp    L
 399 1001010hhhhh111h   call    h
 400 1001010hhhhh110h   jmp     h
 401 1001010rrrrr0101   asr     r
 402 1001010rrrrr0000   com     r
 403 1001010rrrrr1010   dec     r
 404 1001010rrrrr0011   inc     r
 405 1001010rrrrr0110   lsr     r
 406 1001010rrrrr0001   neg     r
 407 1001000rrrrr1111   pop     r
 408 1001001rrrrr1111   push    r
 409 1001010rrrrr0111   ror     r
 410 1001010rrrrr0010   swap    r
 411 00000001ddddrrrr   movw    v,v
 412 00000010ddddrrrr   muls    d,d
 413 000000110ddd0rrr   mulsu   a,a
 414 000000110ddd1rrr   fmul    a,a
 415 000000111ddd0rrr   fmuls   a,a
 416 000000111ddd1rrr   fmulsu  a,a
 417 1001001ddddd0000   sts     i,r
 418 1001000ddddd0000   lds     r,i
 419 10o0oo0dddddbooo   ldd     r,b
 420 100!000dddddee-+   ld      r,e
 421 10o0oo1rrrrrbooo   std     b,r
 422 100!001rrrrree-+   st      e,r
 423 1001010100011001   eicall
 424 1001010000011001   eijmp
 425 @end smallexample