gas/doc/c-avr.texi

   1 @c Copyright 2006, 2007, 2008, 2009, 2011
   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 attiny2313a, attiny24, attiny24a, attiny4313, attiny44, attiny44a, attiny84,
  47 attiny84a, attiny25, attiny45, attiny85, attiny261, attiny261a, attiny461,
  48 attiny461a, attiny861, attiny861a, attiny87, attiny43u, attiny48, attiny88,
  49 at86rf401, ata6289).
  50
  51 Instruction set avr3 is for the classic AVR core with up to 128K program
  52 memory space (MCU types: at43usb355, at76c711).
  53
  54 Instruction set avr31 is for the classic AVR core with exactly 128K program
  55 memory space (MCU types: atmega103, at43usb320).
  56
  57 Instruction set avr35 is for classic AVR core plus MOVW, CALL, and JMP
  58 instructions (MCU types: attiny167, at90usb82, at90usb162, atmega8u2,
  59 atmega16u2, atmega32u2).
  60
  61 Instruction set avr4 is for the enhanced AVR core with up to 8K program
  62 memory space (MCU types: atmega48, atmega48a, atmega48p, atmega8, atmega88,
  63 atmega88a, atmega88p, atmega88pa, atmega8515, atmega8535, atmega8hva, at90pwm1,
  64 at90pwm2, at90pwm2b, at90pwm3, at90pwm3b, at90pwm81).
  65
  66 Instruction set avr5 is for the enhanced AVR core with up to 128K program
  67 memory space (MCU types: atmega16, atmega16a, atmega161, atmega162, atmega163,
  68 atmega164a, atmega164p, atmega165, atmega165a, atmega165p, atmega168,
  69 atmega168a, atmega168p, atmega169, atmega169a, atmega169p, atmega169pa,
  70 atmega32, atmega323, atmega324a, atmega324p, atmega325, atmega325a, atmega325p,
  71 atmega3250, atmega3250a, atmega3250p, atmega328, atmega328p, atmega329,
  72 atmega329a, atmega329p, atmega329pa, atmega3290, atmega3290a, atmega3290p,
  73 atmega406, atmega64, atmega640, atmega644, atmega644a, atmega644p, atmega644pa,
  74 atmega645, atmega645a, atmega645p, atmega6450, atmega6450a, atmega6450p,
  75 atmega649, atmega649a, atmega649p, atmega6490, atmega6490a, atmega6490p,
  76 atmega16hva, atmega16hva2, atmega16hvb, atmega32hvb, atmega64hve, at90can32,
  77 at90can64, at90pwm216, at90pwm316, atmega32c1, atmega64c1, atmega16m1,
  78 atmega32m1, atmega64m1, atmega16u4, atmega32u4, atmega32u6, at90usb646,
  79 at90usb647, at94k, at90scr100).
  80
  81 Instruction set avr51 is for the enhanced AVR core with exactly 128K program
  82 memory space (MCU types: atmega128, atmega1280, atmega1281, atmega1284p,
  83 atmega128rfa1, at90can128, at90usb1286, at90usb1287, m3000).
  84
  85 Instruction set avr6 is for the enhanced AVR core with a 3-byte PC (MCU types:
  86 atmega2560, atmega2561).
  87
  88 @cindex @code{-mall-opcodes} command line option, AVR
  89 @item -mall-opcodes
  90 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  91
  92 @cindex @code{-mno-skip-bug} command line option, AVR
  93 @item -mno-skip-bug
  94 This option disable warnings for skipping two-word instructions.
  95
  96 @cindex @code{-mno-wrap} command line option, AVR
  97 @item -mno-wrap
  98 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  99
 100 @end table
 101
 102
 103 @node AVR Syntax
 104 @section Syntax
 105 @menu
 106 * AVR-Chars::                Special Characters
 107 * AVR-Regs::                 Register Names
 108 * AVR-Modifiers::            Relocatable Expression Modifiers
 109 @end menu
 110
 111 @node AVR-Chars
 112 @subsection Special Characters
 113
 114 @cindex line comment character, AVR
 115 @cindex AVR line comment character
 116
 117 The presence of a @samp{;} anywhere on a line indicates the start of a
 118 comment that extends to the end of that line.
 119
 120 If a @samp{#} appears as the first character of a line, the whole line
 121 is treated as a comment, but in this case the line can also be a
 122 logical line number directive (@pxref{Comments}) or a preprocessor
 123 control command (@pxref{Preprocessing}).
 124
 125 @cindex line separator, AVR
 126 @cindex statement separator, AVR
 127 @cindex AVR line separator
 128
 129 The @samp{$} character can be used instead of a newline to separate
 130 statements.
 131
 132 @node AVR-Regs
 133 @subsection Register Names
 134
 135 @cindex AVR register names
 136 @cindex register names, AVR
 137
 138 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 139 @samp{r1}, ... @samp{r31}.
 140 Six of the 32 registers can be used as three 16-bit indirect address
 141 register pointers for Data Space addressing. One of the these address
 142 pointers can also be used as an address pointer for look up tables in
 143 Flash program memory. These added function registers are the 16-bit
 144 @samp{X}, @samp{Y} and @samp{Z} - registers.
 145
 146 @smallexample
 147 X = @r{r26:r27}
 148 Y = @r{r28:r29}
 149 Z = @r{r30:r31}
 150 @end smallexample
 151
 152 @node AVR-Modifiers
 153 @subsection Relocatable Expression Modifiers
 154
 155 @cindex AVR modifiers
 156 @cindex syntax, AVR
 157
 158 The assembler supports several modifiers when using relocatable addresses
 159 in AVR instruction operands.  The general syntax is the following:
 160
 161 @smallexample
 162 modifier(relocatable-expression)
 163 @end smallexample
 164
 165 @table @code
 166 @cindex symbol modifiers
 167
 168 @item lo8
 169
 170 This modifier allows you to use bits 0 through 7 of
 171 an address expression as 8 bit relocatable expression.
 172
 173 @item hi8
 174
 175 This modifier allows you to use bits 7 through 15 of an address expression
 176 as 8 bit relocatable expression.  This is useful with, for example, the
 177 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 178
 179 For example
 180
 181 @smallexample
 182 ldi r26, lo8(sym+10)
 183 ldi r27, hi8(sym+10)
 184 @end smallexample
 185
 186 @item hh8
 187
 188 This modifier allows you to use bits 16 through 23 of
 189 an address expression as 8 bit relocatable expression.
 190 Also, can be useful for loading 32 bit constants.
 191
 192 @item hlo8
 193
 194 Synonym of @samp{hh8}.
 195
 196 @item hhi8
 197
 198 This modifier allows you to use bits 24 through 31 of
 199 an expression as 8 bit expression. This is useful with, for example, the
 200 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 201 @samp{hhi8}, modifier.
 202
 203 For example
 204
 205 @smallexample
 206 ldi r26, lo8(285774925)
 207 ldi r27, hi8(285774925)
 208 ldi r28, hlo8(285774925)
 209 ldi r29, hhi8(285774925)
 210 ; r29,r28,r27,r26 = 285774925
 211 @end smallexample
 212
 213 @item pm_lo8
 214
 215 This modifier allows you to use bits 0 through 7 of
 216 an address expression as 8 bit relocatable expression.
 217 This modifier useful for addressing data or code from
 218 Flash/Program memory. The using of @samp{pm_lo8} similar
 219 to @samp{lo8}.
 220
 221 @item pm_hi8
 222
 223 This modifier allows you to use bits 8 through 15 of
 224 an address expression as 8 bit relocatable expression.
 225 This modifier useful for addressing data or code from
 226 Flash/Program memory.
 227
 228 @item pm_hh8
 229
 230 This modifier allows you to use bits 15 through 23 of
 231 an address expression as 8 bit relocatable expression.
 232 This modifier useful for addressing data or code from
 233 Flash/Program memory.
 234
 235 @end table
 236
 237 @node AVR Opcodes
 238 @section Opcodes
 239
 240 @cindex AVR opcode summary
 241 @cindex opcode summary, AVR
 242 @cindex mnemonics, AVR
 243 @cindex instruction summary, AVR
 244 For detailed information on the AVR machine instruction set, see
 245 @url{www.atmel.com/products/AVR}.
 246
 247 @code{@value{AS}} implements all the standard AVR opcodes.
 248 The following table summarizes the AVR opcodes, and their arguments.
 249
 250 @smallexample
 251 @i{Legend:}
 252    r   @r{any register}
 253    d   @r{`ldi' register (r16-r31)}
 254    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 255    a   @r{`fmul' register (r16-r23)}
 256    w   @r{`adiw' register (r24,r26,r28,r30)}
 257    e   @r{pointer registers (X,Y,Z)}
 258    b   @r{base pointer register and displacement ([YZ]+disp)}
 259    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 260    M   @r{immediate value from 0 to 255}
 261    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 262    s   @r{immediate value from 0 to 7}
 263    P   @r{Port address value from 0 to 63. (in, out)}
 264    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 265    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 266    i   @r{immediate value}
 267    l   @r{signed pc relative offset from -64 to 63}
 268    L   @r{signed pc relative offset from -2048 to 2047}
 269    h   @r{absolute code address (call, jmp)}
 270    S   @r{immediate value from 0 to 7 (S = s << 4)}
 271    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 272
 273 1001010010001000   clc
 274 1001010011011000   clh
 275 1001010011111000   cli
 276 1001010010101000   cln
 277 1001010011001000   cls
 278 1001010011101000   clt
 279 1001010010111000   clv
 280 1001010010011000   clz
 281 1001010000001000   sec
 282 1001010001011000   seh
 283 1001010001111000   sei
 284 1001010000101000   sen
 285 1001010001001000   ses
 286 1001010001101000   set
 287 1001010000111000   sev
 288 1001010000011000   sez
 289 100101001SSS1000   bclr    S
 290 100101000SSS1000   bset    S
 291 1001010100001001   icall
 292 1001010000001001   ijmp
 293 1001010111001000   lpm     ?
 294 1001000ddddd010+   lpm     r,z
 295 1001010111011000   elpm    ?
 296 1001000ddddd011+   elpm    r,z
 297 0000000000000000   nop
 298 1001010100001000   ret
 299 1001010100011000   reti
 300 1001010110001000   sleep
 301 1001010110011000   break
 302 1001010110101000   wdr
 303 1001010111101000   spm
 304 000111rdddddrrrr   adc     r,r
 305 000011rdddddrrrr   add     r,r
 306 001000rdddddrrrr   and     r,r
 307 000101rdddddrrrr   cp      r,r
 308 000001rdddddrrrr   cpc     r,r
 309 000100rdddddrrrr   cpse    r,r
 310 001001rdddddrrrr   eor     r,r
 311 001011rdddddrrrr   mov     r,r
 312 100111rdddddrrrr   mul     r,r
 313 001010rdddddrrrr   or      r,r
 314 000010rdddddrrrr   sbc     r,r
 315 000110rdddddrrrr   sub     r,r
 316 001001rdddddrrrr   clr     r
 317 000011rdddddrrrr   lsl     r
 318 000111rdddddrrrr   rol     r
 319 001000rdddddrrrr   tst     r
 320 0111KKKKddddKKKK   andi    d,M
 321 0111KKKKddddKKKK   cbr     d,n
 322 1110KKKKddddKKKK   ldi     d,M
 323 11101111dddd1111   ser     d
 324 0110KKKKddddKKKK   ori     d,M
 325 0110KKKKddddKKKK   sbr     d,M
 326 0011KKKKddddKKKK   cpi     d,M
 327 0100KKKKddddKKKK   sbci    d,M
 328 0101KKKKddddKKKK   subi    d,M
 329 1111110rrrrr0sss   sbrc    r,s
 330 1111111rrrrr0sss   sbrs    r,s
 331 1111100ddddd0sss   bld     r,s
 332 1111101ddddd0sss   bst     r,s
 333 10110PPdddddPPPP   in      r,P
 334 10111PPrrrrrPPPP   out     P,r
 335 10010110KKddKKKK   adiw    w,K
 336 10010111KKddKKKK   sbiw    w,K
 337 10011000pppppsss   cbi     p,s
 338 10011010pppppsss   sbi     p,s
 339 10011001pppppsss   sbic    p,s
 340 10011011pppppsss   sbis    p,s
 341 111101lllllll000   brcc    l
 342 111100lllllll000   brcs    l
 343 111100lllllll001   breq    l
 344 111101lllllll100   brge    l
 345 111101lllllll101   brhc    l
 346 111100lllllll101   brhs    l
 347 111101lllllll111   brid    l
 348 111100lllllll111   brie    l
 349 111100lllllll000   brlo    l
 350 111100lllllll100   brlt    l
 351 111100lllllll010   brmi    l
 352 111101lllllll001   brne    l
 353 111101lllllll010   brpl    l
 354 111101lllllll000   brsh    l
 355 111101lllllll110   brtc    l
 356 111100lllllll110   brts    l
 357 111101lllllll011   brvc    l
 358 111100lllllll011   brvs    l
 359 111101lllllllsss   brbc    s,l
 360 111100lllllllsss   brbs    s,l
 361 1101LLLLLLLLLLLL   rcall   L
 362 1100LLLLLLLLLLLL   rjmp    L
 363 1001010hhhhh111h   call    h
 364 1001010hhhhh110h   jmp     h
 365 1001010rrrrr0101   asr     r
 366 1001010rrrrr0000   com     r
 367 1001010rrrrr1010   dec     r
 368 1001010rrrrr0011   inc     r
 369 1001010rrrrr0110   lsr     r
 370 1001010rrrrr0001   neg     r
 371 1001000rrrrr1111   pop     r
 372 1001001rrrrr1111   push    r
 373 1001010rrrrr0111   ror     r
 374 1001010rrrrr0010   swap    r
 375 00000001ddddrrrr   movw    v,v
 376 00000010ddddrrrr   muls    d,d
 377 000000110ddd0rrr   mulsu   a,a
 378 000000110ddd1rrr   fmul    a,a
 379 000000111ddd0rrr   fmuls   a,a
 380 000000111ddd1rrr   fmulsu  a,a
 381 1001001ddddd0000   sts     i,r
 382 1001000ddddd0000   lds     r,i
 383 10o0oo0dddddbooo   ldd     r,b
 384 100!000dddddee-+   ld      r,e
 385 10o0oo1rrrrrbooo   std     b,r
 386 100!001rrrrree-+   st      e,r
 387 1001010100011001   eicall
 388 1001010000011001   eijmp
 389 @end smallexample