gas/doc/c-avr.texi

   1 @c Copyright 2006, 2007, 2008, 2009
   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 attiny25, attiny45, attiny85, attiny261, attiny261a, attiny461, attiny861,
  48 attiny861a, attiny87, attiny43u, attiny48, attiny88, at86rf401, 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, atmega644pa, atmega645, atmega6450, atmega649,
  71 atmega6490, atmega16hva, atmega16hvb, atmega32hvb, at90can32, at90can64,
  72 at90pwm216, at90pwm316, atmega32c1, atmega64c1, atmega16m1, atmega32m1,
  73 atmega64m1, atmega16u4, atmega32u4, atmega32u6, at90usb646, at90usb647, at94k,
  74 at90scr100).
  75
  76 Instruction set avr51 is for the enhanced AVR core with exactly 128K program
  77 memory space (MCU types: atmega128, atmega1280, atmega1281, atmega1284p,
  78 atmega128rfa1, at90can128, at90usb1286, at90usb1287, m3000f, m3000s, m3001b).
  79
  80 Instruction set avr6 is for the enhanced AVR core with a 3-byte PC (MCU types:
  81 atmega2560, atmega2561).
  82
  83 @cindex @code{-mall-opcodes} command line option, AVR
  84 @item -mall-opcodes
  85 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  86
  87 @cindex @code{-mno-skip-bug} command line option, AVR
  88 @item -mno-skip-bug
  89 This option disable warnings for skipping two-word instructions.
  90
  91 @cindex @code{-mno-wrap} command line option, AVR
  92 @item -mno-wrap
  93 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  94
  95 @end table
  96
  97
  98 @node AVR Syntax
  99 @section Syntax
 100 @menu
 101 * AVR-Chars::                Special Characters
 102 * AVR-Regs::                 Register Names
 103 * AVR-Modifiers::            Relocatable Expression Modifiers
 104 @end menu
 105
 106 @node AVR-Chars
 107 @subsection Special Characters
 108
 109 @cindex line comment character, AVR
 110 @cindex AVR line comment character
 111
 112 The presence of a @samp{;} on a line indicates the start of a comment
 113 that extends to the end of the current line.  If a @samp{#} appears as
 114 the first character of a line, the whole line is treated as a comment.
 115
 116 @cindex line separator, AVR
 117 @cindex statement separator, AVR
 118 @cindex AVR line separator
 119
 120 The @samp{$} character can be used instead of a newline to separate
 121 statements.
 122
 123 @node AVR-Regs
 124 @subsection Register Names
 125
 126 @cindex AVR register names
 127 @cindex register names, AVR
 128
 129 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 130 @samp{r1}, ... @samp{r31}.
 131 Six of the 32 registers can be used as three 16-bit indirect address
 132 register pointers for Data Space addressing. One of the these address
 133 pointers can also be used as an address pointer for look up tables in
 134 Flash program memory. These added function registers are the 16-bit
 135 @samp{X}, @samp{Y} and @samp{Z} - registers.
 136
 137 @smallexample
 138 X = @r{r26:r27}
 139 Y = @r{r28:r29}
 140 Z = @r{r30:r31}
 141 @end smallexample
 142
 143 @node AVR-Modifiers
 144 @subsection Relocatable Expression Modifiers
 145
 146 @cindex AVR modifiers
 147 @cindex syntax, AVR
 148
 149 The assembler supports several modifiers when using relocatable addresses
 150 in AVR instruction operands.  The general syntax is the following:
 151
 152 @smallexample
 153 modifier(relocatable-expression)
 154 @end smallexample
 155
 156 @table @code
 157 @cindex symbol modifiers
 158
 159 @item lo8
 160
 161 This modifier allows you to use bits 0 through 7 of
 162 an address expression as 8 bit relocatable expression.
 163
 164 @item hi8
 165
 166 This modifier allows you to use bits 7 through 15 of an address expression
 167 as 8 bit relocatable expression.  This is useful with, for example, the
 168 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 169
 170 For example
 171
 172 @smallexample
 173 ldi r26, lo8(sym+10)
 174 ldi r27, hi8(sym+10)
 175 @end smallexample
 176
 177 @item hh8
 178
 179 This modifier allows you to use bits 16 through 23 of
 180 an address expression as 8 bit relocatable expression.
 181 Also, can be useful for loading 32 bit constants.
 182
 183 @item hlo8
 184
 185 Synonym of @samp{hh8}.
 186
 187 @item hhi8
 188
 189 This modifier allows you to use bits 24 through 31 of
 190 an expression as 8 bit expression. This is useful with, for example, the
 191 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 192 @samp{hhi8}, modifier.
 193
 194 For example
 195
 196 @smallexample
 197 ldi r26, lo8(285774925)
 198 ldi r27, hi8(285774925)
 199 ldi r28, hlo8(285774925)
 200 ldi r29, hhi8(285774925)
 201 ; r29,r28,r27,r26 = 285774925
 202 @end smallexample
 203
 204 @item pm_lo8
 205
 206 This modifier allows you to use bits 0 through 7 of
 207 an address expression as 8 bit relocatable expression.
 208 This modifier useful for addressing data or code from
 209 Flash/Program memory. The using of @samp{pm_lo8} similar
 210 to @samp{lo8}.
 211
 212 @item pm_hi8
 213
 214 This modifier allows you to use bits 8 through 15 of
 215 an address expression as 8 bit relocatable expression.
 216 This modifier useful for addressing data or code from
 217 Flash/Program memory.
 218
 219 @item pm_hh8
 220
 221 This modifier allows you to use bits 15 through 23 of
 222 an address expression as 8 bit relocatable expression.
 223 This modifier useful for addressing data or code from
 224 Flash/Program memory.
 225
 226 @end table
 227
 228 @node AVR Opcodes
 229 @section Opcodes
 230
 231 @cindex AVR opcode summary
 232 @cindex opcode summary, AVR
 233 @cindex mnemonics, AVR
 234 @cindex instruction summary, AVR
 235 For detailed information on the AVR machine instruction set, see
 236 @url{www.atmel.com/products/AVR}.
 237
 238 @code{@value{AS}} implements all the standard AVR opcodes.
 239 The following table summarizes the AVR opcodes, and their arguments.
 240
 241 @smallexample
 242 @i{Legend:}
 243    r   @r{any register}
 244    d   @r{`ldi' register (r16-r31)}
 245    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 246    a   @r{`fmul' register (r16-r23)}
 247    w   @r{`adiw' register (r24,r26,r28,r30)}
 248    e   @r{pointer registers (X,Y,Z)}
 249    b   @r{base pointer register and displacement ([YZ]+disp)}
 250    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 251    M   @r{immediate value from 0 to 255}
 252    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 253    s   @r{immediate value from 0 to 7}
 254    P   @r{Port address value from 0 to 63. (in, out)}
 255    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 256    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 257    i   @r{immediate value}
 258    l   @r{signed pc relative offset from -64 to 63}
 259    L   @r{signed pc relative offset from -2048 to 2047}
 260    h   @r{absolute code address (call, jmp)}
 261    S   @r{immediate value from 0 to 7 (S = s << 4)}
 262    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 263
 264 1001010010001000   clc
 265 1001010011011000   clh
 266 1001010011111000   cli
 267 1001010010101000   cln
 268 1001010011001000   cls
 269 1001010011101000   clt
 270 1001010010111000   clv
 271 1001010010011000   clz
 272 1001010000001000   sec
 273 1001010001011000   seh
 274 1001010001111000   sei
 275 1001010000101000   sen
 276 1001010001001000   ses
 277 1001010001101000   set
 278 1001010000111000   sev
 279 1001010000011000   sez
 280 100101001SSS1000   bclr    S
 281 100101000SSS1000   bset    S
 282 1001010100001001   icall
 283 1001010000001001   ijmp
 284 1001010111001000   lpm     ?
 285 1001000ddddd010+   lpm     r,z
 286 1001010111011000   elpm    ?
 287 1001000ddddd011+   elpm    r,z
 288 0000000000000000   nop
 289 1001010100001000   ret
 290 1001010100011000   reti
 291 1001010110001000   sleep
 292 1001010110011000   break
 293 1001010110101000   wdr
 294 1001010111101000   spm
 295 000111rdddddrrrr   adc     r,r
 296 000011rdddddrrrr   add     r,r
 297 001000rdddddrrrr   and     r,r
 298 000101rdddddrrrr   cp      r,r
 299 000001rdddddrrrr   cpc     r,r
 300 000100rdddddrrrr   cpse    r,r
 301 001001rdddddrrrr   eor     r,r
 302 001011rdddddrrrr   mov     r,r
 303 100111rdddddrrrr   mul     r,r
 304 001010rdddddrrrr   or      r,r
 305 000010rdddddrrrr   sbc     r,r
 306 000110rdddddrrrr   sub     r,r
 307 001001rdddddrrrr   clr     r
 308 000011rdddddrrrr   lsl     r
 309 000111rdddddrrrr   rol     r
 310 001000rdddddrrrr   tst     r
 311 0111KKKKddddKKKK   andi    d,M
 312 0111KKKKddddKKKK   cbr     d,n
 313 1110KKKKddddKKKK   ldi     d,M
 314 11101111dddd1111   ser     d
 315 0110KKKKddddKKKK   ori     d,M
 316 0110KKKKddddKKKK   sbr     d,M
 317 0011KKKKddddKKKK   cpi     d,M
 318 0100KKKKddddKKKK   sbci    d,M
 319 0101KKKKddddKKKK   subi    d,M
 320 1111110rrrrr0sss   sbrc    r,s
 321 1111111rrrrr0sss   sbrs    r,s
 322 1111100ddddd0sss   bld     r,s
 323 1111101ddddd0sss   bst     r,s
 324 10110PPdddddPPPP   in      r,P
 325 10111PPrrrrrPPPP   out     P,r
 326 10010110KKddKKKK   adiw    w,K
 327 10010111KKddKKKK   sbiw    w,K
 328 10011000pppppsss   cbi     p,s
 329 10011010pppppsss   sbi     p,s
 330 10011001pppppsss   sbic    p,s
 331 10011011pppppsss   sbis    p,s
 332 111101lllllll000   brcc    l
 333 111100lllllll000   brcs    l
 334 111100lllllll001   breq    l
 335 111101lllllll100   brge    l
 336 111101lllllll101   brhc    l
 337 111100lllllll101   brhs    l
 338 111101lllllll111   brid    l
 339 111100lllllll111   brie    l
 340 111100lllllll000   brlo    l
 341 111100lllllll100   brlt    l
 342 111100lllllll010   brmi    l
 343 111101lllllll001   brne    l
 344 111101lllllll010   brpl    l
 345 111101lllllll000   brsh    l
 346 111101lllllll110   brtc    l
 347 111100lllllll110   brts    l
 348 111101lllllll011   brvc    l
 349 111100lllllll011   brvs    l
 350 111101lllllllsss   brbc    s,l
 351 111100lllllllsss   brbs    s,l
 352 1101LLLLLLLLLLLL   rcall   L
 353 1100LLLLLLLLLLLL   rjmp    L
 354 1001010hhhhh111h   call    h
 355 1001010hhhhh110h   jmp     h
 356 1001010rrrrr0101   asr     r
 357 1001010rrrrr0000   com     r
 358 1001010rrrrr1010   dec     r
 359 1001010rrrrr0011   inc     r
 360 1001010rrrrr0110   lsr     r
 361 1001010rrrrr0001   neg     r
 362 1001000rrrrr1111   pop     r
 363 1001001rrrrr1111   push    r
 364 1001010rrrrr0111   ror     r
 365 1001010rrrrr0010   swap    r
 366 00000001ddddrrrr   movw    v,v
 367 00000010ddddrrrr   muls    d,d
 368 000000110ddd0rrr   mulsu   a,a
 369 000000110ddd1rrr   fmul    a,a
 370 000000111ddd0rrr   fmuls   a,a
 371 000000111ddd1rrr   fmulsu  a,a
 372 1001001ddddd0000   sts     i,r
 373 1001000ddddd0000   lds     r,i
 374 10o0oo0dddddbooo   ldd     r,b
 375 100!000dddddee-+   ld      r,e
 376 10o0oo1rrrrrbooo   std     b,r
 377 100!001rrrrree-+   st      e,r
 378 1001010100011001   eicall
 379 1001010000011001   eijmp
 380 @end smallexample