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
  86 program memory space (MCU types: atmega128, atmega128a, atmega1280,
  87 atmega1281, atmega1284, atmega1284p, atmega128rfa1, atmega128rfr2,
  88 atmega1284rfr2, at90can128, at90usb1286, at90usb1287, m3000).
  89
  90 Instruction set avr6 is for the enhanced AVR core with a 3-byte PC
  91 (MCU types: atmega2560, atmega2561, atmega256rfr2, atmega2564rfr2).
  92
  93 Instruction set avrxmega2 is for the XMEGA AVR core with 8K to 64K
  94 program memory space and less than 64K data space (MCU types:
  95 atxmega16a4, atxmega16a4u, atxmega16c4, atxmega16d4, atxmega16x1,
  96 atxmega32a4, atxmega32a4u, atxmega32c4, atxmega32d4, atxmega16e5,
  97 atxmega8e5, atxmega32e5, atxmega32x1).
  98
  99 Instruction set avrxmega3 is for the XMEGA AVR core with 8K to 64K
 100 program memory space and greater than 64K data space (MCU types:
 101 none).
 102
 103 Instruction set avrxmega4 is for the XMEGA AVR core with up to 64K
 104 program memory space and less than 64K data space (MCU types:
 105 atxmega64a3, atxmega64a3u, atxmega64a4u, atxmega64b1, atxmega64b3,
 106 atxmega64c3, atxmega64d3, atxmega64d4).
 107
 108 Instruction set avrxmega5 is for the XMEGA AVR core with up to 64K
 109 program memory space and greater than 64K data space (MCU types:
 110 atxmega64a1, atxmega64a1u).
 111
 112 Instruction set avrxmega6 is for the XMEGA AVR core with larger than
 113 64K program memory space and less than 64K data space (MCU types:
 114 atxmega128a3, atxmega128a3u, atxmega128c3, atxmega128d3, atxmega128d4,
 115 atxmega192a3, atxmega192a3u, atxmega128b1, atxmega128b3, atxmega192c3,
 116 atxmega192d3, atxmega256a3, atxmega256a3u, atxmega256a3b,
 117 atxmega256a3bu, atxmega256c3, atxmega256d3, atxmega384c3,
 118 atxmega256d3).
 119
 120 Instruction set avrxmega7 is for the XMEGA AVR core with larger than
 121 64K program memory space and greater than 64K data space (MCU types:
 122 atxmega128a1, atxmega128a1u, atxmega128a4u).
 123
 124 Instruction set avrtiny is for the ATtiny4/5/9/10/20/40
 125 microcontrollers.
 126
 127 @cindex @code{-mall-opcodes} command line option, AVR
 128 @item -mall-opcodes
 129 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
 130
 131 @cindex @code{-mno-skip-bug} command line option, AVR
 132 @item -mno-skip-bug
 133 This option disable warnings for skipping two-word instructions.
 134
 135 @cindex @code{-mno-wrap} command line option, AVR
 136 @item -mno-wrap
 137 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
 138
 139 @cindex @code{-mrmw} command line option, AVR
 140 @item -mrmw
 141 Accept Read-Modify-Write (@code{XCH,LAC,LAS,LAT}) instructions.
 142
 143 @end table
 144
 145
 146 @node AVR Syntax
 147 @section Syntax
 148 @menu
 149 * AVR-Chars::                Special Characters
 150 * AVR-Regs::                 Register Names
 151 * AVR-Modifiers::            Relocatable Expression Modifiers
 152 @end menu
 153
 154 @node AVR-Chars
 155 @subsection Special Characters
 156
 157 @cindex line comment character, AVR
 158 @cindex AVR line comment character
 159
 160 The presence of a @samp{;} anywhere on a line indicates the start of a
 161 comment that extends to the end of that line.
 162
 163 If a @samp{#} appears as the first character of a line, the whole line
 164 is treated as a comment, but in this case the line can also be a
 165 logical line number directive (@pxref{Comments}) or a preprocessor
 166 control command (@pxref{Preprocessing}).
 167
 168 @cindex line separator, AVR
 169 @cindex statement separator, AVR
 170 @cindex AVR line separator
 171
 172 The @samp{$} character can be used instead of a newline to separate
 173 statements.
 174
 175 @node AVR-Regs
 176 @subsection Register Names
 177
 178 @cindex AVR register names
 179 @cindex register names, AVR
 180
 181 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 182 @samp{r1}, ... @samp{r31}.
 183 Six of the 32 registers can be used as three 16-bit indirect address
 184 register pointers for Data Space addressing. One of the these address
 185 pointers can also be used as an address pointer for look up tables in
 186 Flash program memory. These added function registers are the 16-bit
 187 @samp{X}, @samp{Y} and @samp{Z} - registers.
 188
 189 @smallexample
 190 X = @r{r26:r27}
 191 Y = @r{r28:r29}
 192 Z = @r{r30:r31}
 193 @end smallexample
 194
 195 @node AVR-Modifiers
 196 @subsection Relocatable Expression Modifiers
 197
 198 @cindex AVR modifiers
 199 @cindex syntax, AVR
 200
 201 The assembler supports several modifiers when using relocatable addresses
 202 in AVR instruction operands.  The general syntax is the following:
 203
 204 @smallexample
 205 modifier(relocatable-expression)
 206 @end smallexample
 207
 208 @table @code
 209 @cindex symbol modifiers
 210
 211 @item lo8
 212
 213 This modifier allows you to use bits 0 through 7 of
 214 an address expression as 8 bit relocatable expression.
 215
 216 @item hi8
 217
 218 This modifier allows you to use bits 7 through 15 of an address expression
 219 as 8 bit relocatable expression.  This is useful with, for example, the
 220 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 221
 222 For example
 223
 224 @smallexample
 225 ldi r26, lo8(sym+10)
 226 ldi r27, hi8(sym+10)
 227 @end smallexample
 228
 229 @item hh8
 230
 231 This modifier allows you to use bits 16 through 23 of
 232 an address expression as 8 bit relocatable expression.
 233 Also, can be useful for loading 32 bit constants.
 234
 235 @item hlo8
 236
 237 Synonym of @samp{hh8}.
 238
 239 @item hhi8
 240
 241 This modifier allows you to use bits 24 through 31 of
 242 an expression as 8 bit expression. This is useful with, for example, the
 243 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 244 @samp{hhi8}, modifier.
 245
 246 For example
 247
 248 @smallexample
 249 ldi r26, lo8(285774925)
 250 ldi r27, hi8(285774925)
 251 ldi r28, hlo8(285774925)
 252 ldi r29, hhi8(285774925)
 253 ; r29,r28,r27,r26 = 285774925
 254 @end smallexample
 255
 256 @item pm_lo8
 257
 258 This modifier allows you to use bits 0 through 7 of
 259 an address expression as 8 bit relocatable expression.
 260 This modifier useful for addressing data or code from
 261 Flash/Program memory. The using of @samp{pm_lo8} similar
 262 to @samp{lo8}.
 263
 264 @item pm_hi8
 265
 266 This modifier allows you to use bits 8 through 15 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 @item pm_hh8
 272
 273 This modifier allows you to use bits 15 through 23 of
 274 an address expression as 8 bit relocatable expression.
 275 This modifier useful for addressing data or code from
 276 Flash/Program memory.
 277
 278 @end table
 279
 280 @node AVR Opcodes
 281 @section Opcodes
 282
 283 @cindex AVR opcode summary
 284 @cindex opcode summary, AVR
 285 @cindex mnemonics, AVR
 286 @cindex instruction summary, AVR
 287 For detailed information on the AVR machine instruction set, see
 288 @url{www.atmel.com/products/AVR}.
 289
 290 @code{@value{AS}} implements all the standard AVR opcodes.
 291 The following table summarizes the AVR opcodes, and their arguments.
 292
 293 @smallexample
 294 @i{Legend:}
 295    r   @r{any register}
 296    d   @r{`ldi' register (r16-r31)}
 297    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 298    a   @r{`fmul' register (r16-r23)}
 299    w   @r{`adiw' register (r24,r26,r28,r30)}
 300    e   @r{pointer registers (X,Y,Z)}
 301    b   @r{base pointer register and displacement ([YZ]+disp)}
 302    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 303    M   @r{immediate value from 0 to 255}
 304    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 305    s   @r{immediate value from 0 to 7}
 306    P   @r{Port address value from 0 to 63. (in, out)}
 307    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 308    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 309    i   @r{immediate value}
 310    l   @r{signed pc relative offset from -64 to 63}
 311    L   @r{signed pc relative offset from -2048 to 2047}
 312    h   @r{absolute code address (call, jmp)}
 313    S   @r{immediate value from 0 to 7 (S = s << 4)}
 314    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 315
 316 1001010010001000   clc
 317 1001010011011000   clh
 318 1001010011111000   cli
 319 1001010010101000   cln
 320 1001010011001000   cls
 321 1001010011101000   clt
 322 1001010010111000   clv
 323 1001010010011000   clz
 324 1001010000001000   sec
 325 1001010001011000   seh
 326 1001010001111000   sei
 327 1001010000101000   sen
 328 1001010001001000   ses
 329 1001010001101000   set
 330 1001010000111000   sev
 331 1001010000011000   sez
 332 100101001SSS1000   bclr    S
 333 100101000SSS1000   bset    S
 334 1001010100001001   icall
 335 1001010000001001   ijmp
 336 1001010111001000   lpm     ?
 337 1001000ddddd010+   lpm     r,z
 338 1001010111011000   elpm    ?
 339 1001000ddddd011+   elpm    r,z
 340 0000000000000000   nop
 341 1001010100001000   ret
 342 1001010100011000   reti
 343 1001010110001000   sleep
 344 1001010110011000   break
 345 1001010110101000   wdr
 346 1001010111101000   spm
 347 000111rdddddrrrr   adc     r,r
 348 000011rdddddrrrr   add     r,r
 349 001000rdddddrrrr   and     r,r
 350 000101rdddddrrrr   cp      r,r
 351 000001rdddddrrrr   cpc     r,r
 352 000100rdddddrrrr   cpse    r,r
 353 001001rdddddrrrr   eor     r,r
 354 001011rdddddrrrr   mov     r,r
 355 100111rdddddrrrr   mul     r,r
 356 001010rdddddrrrr   or      r,r
 357 000010rdddddrrrr   sbc     r,r
 358 000110rdddddrrrr   sub     r,r
 359 001001rdddddrrrr   clr     r
 360 000011rdddddrrrr   lsl     r
 361 000111rdddddrrrr   rol     r
 362 001000rdddddrrrr   tst     r
 363 0111KKKKddddKKKK   andi    d,M
 364 0111KKKKddddKKKK   cbr     d,n
 365 1110KKKKddddKKKK   ldi     d,M
 366 11101111dddd1111   ser     d
 367 0110KKKKddddKKKK   ori     d,M
 368 0110KKKKddddKKKK   sbr     d,M
 369 0011KKKKddddKKKK   cpi     d,M
 370 0100KKKKddddKKKK   sbci    d,M
 371 0101KKKKddddKKKK   subi    d,M
 372 1111110rrrrr0sss   sbrc    r,s
 373 1111111rrrrr0sss   sbrs    r,s
 374 1111100ddddd0sss   bld     r,s
 375 1111101ddddd0sss   bst     r,s
 376 10110PPdddddPPPP   in      r,P
 377 10111PPrrrrrPPPP   out     P,r
 378 10010110KKddKKKK   adiw    w,K
 379 10010111KKddKKKK   sbiw    w,K
 380 10011000pppppsss   cbi     p,s
 381 10011010pppppsss   sbi     p,s
 382 10011001pppppsss   sbic    p,s
 383 10011011pppppsss   sbis    p,s
 384 111101lllllll000   brcc    l
 385 111100lllllll000   brcs    l
 386 111100lllllll001   breq    l
 387 111101lllllll100   brge    l
 388 111101lllllll101   brhc    l
 389 111100lllllll101   brhs    l
 390 111101lllllll111   brid    l
 391 111100lllllll111   brie    l
 392 111100lllllll000   brlo    l
 393 111100lllllll100   brlt    l
 394 111100lllllll010   brmi    l
 395 111101lllllll001   brne    l
 396 111101lllllll010   brpl    l
 397 111101lllllll000   brsh    l
 398 111101lllllll110   brtc    l
 399 111100lllllll110   brts    l
 400 111101lllllll011   brvc    l
 401 111100lllllll011   brvs    l
 402 111101lllllllsss   brbc    s,l
 403 111100lllllllsss   brbs    s,l
 404 1101LLLLLLLLLLLL   rcall   L
 405 1100LLLLLLLLLLLL   rjmp    L
 406 1001010hhhhh111h   call    h
 407 1001010hhhhh110h   jmp     h
 408 1001010rrrrr0101   asr     r
 409 1001010rrrrr0000   com     r
 410 1001010rrrrr1010   dec     r
 411 1001010rrrrr0011   inc     r
 412 1001010rrrrr0110   lsr     r
 413 1001010rrrrr0001   neg     r
 414 1001000rrrrr1111   pop     r
 415 1001001rrrrr1111   push    r
 416 1001010rrrrr0111   ror     r
 417 1001010rrrrr0010   swap    r
 418 00000001ddddrrrr   movw    v,v
 419 00000010ddddrrrr   muls    d,d
 420 000000110ddd0rrr   mulsu   a,a
 421 000000110ddd1rrr   fmul    a,a
 422 000000111ddd0rrr   fmuls   a,a
 423 000000111ddd1rrr   fmulsu  a,a
 424 1001001ddddd0000   sts     i,r
 425 1001000ddddd0000   lds     r,i
 426 10o0oo0dddddbooo   ldd     r,b
 427 100!000dddddee-+   ld      r,e
 428 10o0oo1rrrrrbooo   std     b,r
 429 100!001rrrrree-+   st      e,r
 430 1001010100011001   eicall
 431 1001010000011001   eijmp
 432 @end smallexample