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 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{;} on a line indicates the start of a comment
 118 that extends to the end of the current line.  If a @samp{#} appears as
 119 the first character of a line, the whole line is treated as a comment.
 120
 121 @cindex line separator, AVR
 122 @cindex statement separator, AVR
 123 @cindex AVR line separator
 124
 125 The @samp{$} character can be used instead of a newline to separate
 126 statements.
 127
 128 @node AVR-Regs
 129 @subsection Register Names
 130
 131 @cindex AVR register names
 132 @cindex register names, AVR
 133
 134 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 135 @samp{r1}, ... @samp{r31}.
 136 Six of the 32 registers can be used as three 16-bit indirect address
 137 register pointers for Data Space addressing. One of the these address
 138 pointers can also be used as an address pointer for look up tables in
 139 Flash program memory. These added function registers are the 16-bit
 140 @samp{X}, @samp{Y} and @samp{Z} - registers.
 141
 142 @smallexample
 143 X = @r{r26:r27}
 144 Y = @r{r28:r29}
 145 Z = @r{r30:r31}
 146 @end smallexample
 147
 148 @node AVR-Modifiers
 149 @subsection Relocatable Expression Modifiers
 150
 151 @cindex AVR modifiers
 152 @cindex syntax, AVR
 153
 154 The assembler supports several modifiers when using relocatable addresses
 155 in AVR instruction operands.  The general syntax is the following:
 156
 157 @smallexample
 158 modifier(relocatable-expression)
 159 @end smallexample
 160
 161 @table @code
 162 @cindex symbol modifiers
 163
 164 @item lo8
 165
 166 This modifier allows you to use bits 0 through 7 of
 167 an address expression as 8 bit relocatable expression.
 168
 169 @item hi8
 170
 171 This modifier allows you to use bits 7 through 15 of an address expression
 172 as 8 bit relocatable expression.  This is useful with, for example, the
 173 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 174
 175 For example
 176
 177 @smallexample
 178 ldi r26, lo8(sym+10)
 179 ldi r27, hi8(sym+10)
 180 @end smallexample
 181
 182 @item hh8
 183
 184 This modifier allows you to use bits 16 through 23 of
 185 an address expression as 8 bit relocatable expression.
 186 Also, can be useful for loading 32 bit constants.
 187
 188 @item hlo8
 189
 190 Synonym of @samp{hh8}.
 191
 192 @item hhi8
 193
 194 This modifier allows you to use bits 24 through 31 of
 195 an expression as 8 bit expression. This is useful with, for example, the
 196 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 197 @samp{hhi8}, modifier.
 198
 199 For example
 200
 201 @smallexample
 202 ldi r26, lo8(285774925)
 203 ldi r27, hi8(285774925)
 204 ldi r28, hlo8(285774925)
 205 ldi r29, hhi8(285774925)
 206 ; r29,r28,r27,r26 = 285774925
 207 @end smallexample
 208
 209 @item pm_lo8
 210
 211 This modifier allows you to use bits 0 through 7 of
 212 an address expression as 8 bit relocatable expression.
 213 This modifier useful for addressing data or code from
 214 Flash/Program memory. The using of @samp{pm_lo8} similar
 215 to @samp{lo8}.
 216
 217 @item pm_hi8
 218
 219 This modifier allows you to use bits 8 through 15 of
 220 an address expression as 8 bit relocatable expression.
 221 This modifier useful for addressing data or code from
 222 Flash/Program memory.
 223
 224 @item pm_hh8
 225
 226 This modifier allows you to use bits 15 through 23 of
 227 an address expression as 8 bit relocatable expression.
 228 This modifier useful for addressing data or code from
 229 Flash/Program memory.
 230
 231 @end table
 232
 233 @node AVR Opcodes
 234 @section Opcodes
 235
 236 @cindex AVR opcode summary
 237 @cindex opcode summary, AVR
 238 @cindex mnemonics, AVR
 239 @cindex instruction summary, AVR
 240 For detailed information on the AVR machine instruction set, see
 241 @url{www.atmel.com/products/AVR}.
 242
 243 @code{@value{AS}} implements all the standard AVR opcodes.
 244 The following table summarizes the AVR opcodes, and their arguments.
 245
 246 @smallexample
 247 @i{Legend:}
 248    r   @r{any register}
 249    d   @r{`ldi' register (r16-r31)}
 250    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 251    a   @r{`fmul' register (r16-r23)}
 252    w   @r{`adiw' register (r24,r26,r28,r30)}
 253    e   @r{pointer registers (X,Y,Z)}
 254    b   @r{base pointer register and displacement ([YZ]+disp)}
 255    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 256    M   @r{immediate value from 0 to 255}
 257    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 258    s   @r{immediate value from 0 to 7}
 259    P   @r{Port address value from 0 to 63. (in, out)}
 260    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 261    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 262    i   @r{immediate value}
 263    l   @r{signed pc relative offset from -64 to 63}
 264    L   @r{signed pc relative offset from -2048 to 2047}
 265    h   @r{absolute code address (call, jmp)}
 266    S   @r{immediate value from 0 to 7 (S = s << 4)}
 267    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 268
 269 1001010010001000   clc
 270 1001010011011000   clh
 271 1001010011111000   cli
 272 1001010010101000   cln
 273 1001010011001000   cls
 274 1001010011101000   clt
 275 1001010010111000   clv
 276 1001010010011000   clz
 277 1001010000001000   sec
 278 1001010001011000   seh
 279 1001010001111000   sei
 280 1001010000101000   sen
 281 1001010001001000   ses
 282 1001010001101000   set
 283 1001010000111000   sev
 284 1001010000011000   sez
 285 100101001SSS1000   bclr    S
 286 100101000SSS1000   bset    S
 287 1001010100001001   icall
 288 1001010000001001   ijmp
 289 1001010111001000   lpm     ?
 290 1001000ddddd010+   lpm     r,z
 291 1001010111011000   elpm    ?
 292 1001000ddddd011+   elpm    r,z
 293 0000000000000000   nop
 294 1001010100001000   ret
 295 1001010100011000   reti
 296 1001010110001000   sleep
 297 1001010110011000   break
 298 1001010110101000   wdr
 299 1001010111101000   spm
 300 000111rdddddrrrr   adc     r,r
 301 000011rdddddrrrr   add     r,r
 302 001000rdddddrrrr   and     r,r
 303 000101rdddddrrrr   cp      r,r
 304 000001rdddddrrrr   cpc     r,r
 305 000100rdddddrrrr   cpse    r,r
 306 001001rdddddrrrr   eor     r,r
 307 001011rdddddrrrr   mov     r,r
 308 100111rdddddrrrr   mul     r,r
 309 001010rdddddrrrr   or      r,r
 310 000010rdddddrrrr   sbc     r,r
 311 000110rdddddrrrr   sub     r,r
 312 001001rdddddrrrr   clr     r
 313 000011rdddddrrrr   lsl     r
 314 000111rdddddrrrr   rol     r
 315 001000rdddddrrrr   tst     r
 316 0111KKKKddddKKKK   andi    d,M
 317 0111KKKKddddKKKK   cbr     d,n
 318 1110KKKKddddKKKK   ldi     d,M
 319 11101111dddd1111   ser     d
 320 0110KKKKddddKKKK   ori     d,M
 321 0110KKKKddddKKKK   sbr     d,M
 322 0011KKKKddddKKKK   cpi     d,M
 323 0100KKKKddddKKKK   sbci    d,M
 324 0101KKKKddddKKKK   subi    d,M
 325 1111110rrrrr0sss   sbrc    r,s
 326 1111111rrrrr0sss   sbrs    r,s
 327 1111100ddddd0sss   bld     r,s
 328 1111101ddddd0sss   bst     r,s
 329 10110PPdddddPPPP   in      r,P
 330 10111PPrrrrrPPPP   out     P,r
 331 10010110KKddKKKK   adiw    w,K
 332 10010111KKddKKKK   sbiw    w,K
 333 10011000pppppsss   cbi     p,s
 334 10011010pppppsss   sbi     p,s
 335 10011001pppppsss   sbic    p,s
 336 10011011pppppsss   sbis    p,s
 337 111101lllllll000   brcc    l
 338 111100lllllll000   brcs    l
 339 111100lllllll001   breq    l
 340 111101lllllll100   brge    l
 341 111101lllllll101   brhc    l
 342 111100lllllll101   brhs    l
 343 111101lllllll111   brid    l
 344 111100lllllll111   brie    l
 345 111100lllllll000   brlo    l
 346 111100lllllll100   brlt    l
 347 111100lllllll010   brmi    l
 348 111101lllllll001   brne    l
 349 111101lllllll010   brpl    l
 350 111101lllllll000   brsh    l
 351 111101lllllll110   brtc    l
 352 111100lllllll110   brts    l
 353 111101lllllll011   brvc    l
 354 111100lllllll011   brvs    l
 355 111101lllllllsss   brbc    s,l
 356 111100lllllllsss   brbs    s,l
 357 1101LLLLLLLLLLLL   rcall   L
 358 1100LLLLLLLLLLLL   rjmp    L
 359 1001010hhhhh111h   call    h
 360 1001010hhhhh110h   jmp     h
 361 1001010rrrrr0101   asr     r
 362 1001010rrrrr0000   com     r
 363 1001010rrrrr1010   dec     r
 364 1001010rrrrr0011   inc     r
 365 1001010rrrrr0110   lsr     r
 366 1001010rrrrr0001   neg     r
 367 1001000rrrrr1111   pop     r
 368 1001001rrrrr1111   push    r
 369 1001010rrrrr0111   ror     r
 370 1001010rrrrr0010   swap    r
 371 00000001ddddrrrr   movw    v,v
 372 00000010ddddrrrr   muls    d,d
 373 000000110ddd0rrr   mulsu   a,a
 374 000000110ddd1rrr   fmul    a,a
 375 000000111ddd0rrr   fmuls   a,a
 376 000000111ddd1rrr   fmulsu  a,a
 377 1001001ddddd0000   sts     i,r
 378 1001000ddddd0000   lds     r,i
 379 10o0oo0dddddbooo   ldd     r,b
 380 100!000dddddee-+   ld      r,e
 381 10o0oo1rrrrrbooo   std     b,r
 382 100!001rrrrree-+   st      e,r
 383 1001010100011001   eicall
 384 1001010000011001   eijmp
 385 @end smallexample