gas/doc/c-avr.texi

   1 @c Copyright 2006
   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, attiny10,
  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, attiny22,
  41 attiny26, at90s2333, at90s2343, at90s4414, at90s4433, at90s4434,
  42 at90s8515, at90c8534, at90s8535, at86rf401, attiny13, attiny2313,
  43 attiny261, attiny461, attiny861, attiny24, attiny44, attiny84, attiny25,
  44 attiny45, attiny85).
  45
  46 Instruction set avr3 is for the classic AVR core with up to 128K program
  47 memory space (MCU types: atmega103, atmega603, at43usb320, at43usb355,
  48 at76c711).
  49
  50 Instruction set avr4 is for the enhanced AVR core with up to 8K program
  51 memory space (MCU types: atmega48, atmega8, atmega83, atmega85, atmega88,
  52 atmega8515, atmega8535, atmega8hva, at90pwm1, at90pwm2, at90pwm3).
  53
  54 Instruction set avr5 is for the enhanced AVR core with up to 128K program
  55 memory space (MCU types: atmega16, atmega161, atmega162, atmega163,
  56 atmega164p, atmega165, atmega165p, atmega168, atmega169, atmega169p,
  57 atmega32, atmega323, atmega324p, atmega325, atmega325p, atmega329,
  58 atmega329p, atmega3250, atmega3250p, atmega3290, atmega3290p, atmega406,
  59 atmega64, atmega640, atmega644, atmega644p, atmega128, atmega1280,
  60 atmega1281, atmega645, atmega649, atmega6450, atmega6490, atmega16hva,
  61 at90can32, at90can64, at90can128, at90usb82, at90usb162, at90usb646,
  62 at90usb647, at90usb1286, at90usb1287, at94k).
  63
  64 Instruction set avr6 is for the enhanced AVR core with 256K program
  65 memory space (MCU types: atmega2560, atmega2561).
  66
  67 @cindex @code{-mall-opcodes} command line option, AVR
  68 @item -mall-opcodes
  69 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  70
  71 @cindex @code{-mno-skip-bug} command line option, AVR
  72 @item -mno-skip-bug
  73 This option disable warnings for skipping two-word instructions.
  74
  75 @cindex @code{-mno-wrap} command line option, AVR
  76 @item -mno-wrap
  77 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  78
  79 @end table
  80
  81
  82 @node AVR Syntax
  83 @section Syntax
  84 @menu
  85 * AVR-Chars::                Special Characters
  86 * AVR-Regs::                 Register Names
  87 * AVR-Modifiers::            Relocatable Expression Modifiers
  88 @end menu
  89
  90 @node AVR-Chars
  91 @subsection Special Characters
  92
  93 @cindex line comment character, AVR
  94 @cindex AVR line comment character
  95
  96 The presence of a @samp{;} on a line indicates the start of a comment
  97 that extends to the end of the current line.  If a @samp{#} appears as
  98 the first character of a line, the whole line is treated as a comment.
  99
 100 @cindex line separator, AVR
 101 @cindex statement separator, AVR
 102 @cindex AVR line separator
 103
 104 The @samp{$} character can be used instead of a newline to separate
 105 statements.
 106
 107 @node AVR-Regs
 108 @subsection Register Names
 109
 110 @cindex AVR register names
 111 @cindex register names, AVR
 112
 113 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 114 @samp{r1}, ... @samp{r31}.
 115 Six of the 32 registers can be used as three 16-bit indirect address
 116 register pointers for Data Space addressing. One of the these address
 117 pointers can also be used as an address pointer for look up tables in
 118 Flash program memory. These added function registers are the 16-bit
 119 @samp{X}, @samp{Y} and @samp{Z} - registers.
 120
 121 @smallexample
 122 X = @r{r26:r27}
 123 Y = @r{r28:r29}
 124 Z = @r{r30:r31}
 125 @end smallexample
 126
 127 @node AVR-Modifiers
 128 @subsection Relocatable Expression Modifiers
 129
 130 @cindex AVR modifiers
 131 @cindex syntax, AVR
 132
 133 The assembler supports several modifiers when using relocatable addresses
 134 in AVR instruction operands.  The general syntax is the following:
 135
 136 @smallexample
 137 modifier(relocatable-expression)
 138 @end smallexample
 139
 140 @table @code
 141 @cindex symbol modifiers
 142
 143 @item lo8
 144
 145 This modifier allows you to use bits 0 through 7 of
 146 an address expression as 8 bit relocatable expression.
 147
 148 @item hi8
 149
 150 This modifier allows you to use bits 7 through 15 of an address expression
 151 as 8 bit relocatable expression.  This is useful with, for example, the
 152 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 153
 154 For example
 155
 156 @smallexample
 157 ldi r26, lo8(sym+10)
 158 ldi r27, hi8(sym+10)
 159 @end smallexample
 160
 161 @item hh8
 162
 163 This modifier allows you to use bits 16 through 23 of
 164 an address expression as 8 bit relocatable expression.
 165 Also, can be useful for loading 32 bit constants.
 166
 167 @item hlo8
 168
 169 Synonym of @samp{hh8}.
 170
 171 @item hhi8
 172
 173 This modifier allows you to use bits 24 through 31 of
 174 an expression as 8 bit expression. This is useful with, for example, the
 175 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 176 @samp{hhi8}, modifier.
 177
 178 For example
 179
 180 @smallexample
 181 ldi r26, lo8(285774925)
 182 ldi r27, hi8(285774925)
 183 ldi r28, hlo8(285774925)
 184 ldi r29, hhi8(285774925)
 185 ; r29,r28,r27,r26 = 285774925
 186 @end smallexample
 187
 188 @item pm_lo8
 189
 190 This modifier allows you to use bits 0 through 7 of
 191 an address expression as 8 bit relocatable expression.
 192 This modifier useful for addressing data or code from
 193 Flash/Program memory. The using of @samp{pm_lo8} similar
 194 to @samp{lo8}.
 195
 196 @item pm_hi8
 197
 198 This modifier allows you to use bits 8 through 15 of
 199 an address expression as 8 bit relocatable expression.
 200 This modifier useful for addressing data or code from
 201 Flash/Program memory.
 202
 203 @item pm_hh8
 204
 205 This modifier allows you to use bits 15 through 23 of
 206 an address expression as 8 bit relocatable expression.
 207 This modifier useful for addressing data or code from
 208 Flash/Program memory.
 209
 210 @end table
 211
 212 @node AVR Opcodes
 213 @section Opcodes
 214
 215 @cindex AVR opcode summary
 216 @cindex opcode summary, AVR
 217 @cindex mnemonics, AVR
 218 @cindex instruction summary, AVR
 219 For detailed information on the AVR machine instruction set, see
 220 @url{www.atmel.com/products/AVR}.
 221
 222 @code{@value{AS}} implements all the standard AVR opcodes.
 223 The following table summarizes the AVR opcodes, and their arguments.
 224
 225 @smallexample
 226 @i{Legend:}
 227    r   @r{any register}
 228    d   @r{`ldi' register (r16-r31)}
 229    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 230    a   @r{`fmul' register (r16-r23)}
 231    w   @r{`adiw' register (r24,r26,r28,r30)}
 232    e   @r{pointer registers (X,Y,Z)}
 233    b   @r{base pointer register and displacement ([YZ]+disp)}
 234    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 235    M   @r{immediate value from 0 to 255}
 236    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 237    s   @r{immediate value from 0 to 7}
 238    P   @r{Port address value from 0 to 63. (in, out)}
 239    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 240    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 241    i   @r{immediate value}
 242    l   @r{signed pc relative offset from -64 to 63}
 243    L   @r{signed pc relative offset from -2048 to 2047}
 244    h   @r{absolute code address (call, jmp)}
 245    S   @r{immediate value from 0 to 7 (S = s << 4)}
 246    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 247
 248 1001010010001000   clc
 249 1001010011011000   clh
 250 1001010011111000   cli
 251 1001010010101000   cln
 252 1001010011001000   cls
 253 1001010011101000   clt
 254 1001010010111000   clv
 255 1001010010011000   clz
 256 1001010000001000   sec
 257 1001010001011000   seh
 258 1001010001111000   sei
 259 1001010000101000   sen
 260 1001010001001000   ses
 261 1001010001101000   set
 262 1001010000111000   sev
 263 1001010000011000   sez
 264 100101001SSS1000   bclr    S
 265 100101000SSS1000   bset    S
 266 1001010100001001   icall
 267 1001010000001001   ijmp
 268 1001010111001000   lpm     ?
 269 1001000ddddd010+   lpm     r,z
 270 1001010111011000   elpm    ?
 271 1001000ddddd011+   elpm    r,z
 272 0000000000000000   nop
 273 1001010100001000   ret
 274 1001010100011000   reti
 275 1001010110001000   sleep
 276 1001010110011000   break
 277 1001010110101000   wdr
 278 1001010111101000   spm
 279 000111rdddddrrrr   adc     r,r
 280 000011rdddddrrrr   add     r,r
 281 001000rdddddrrrr   and     r,r
 282 000101rdddddrrrr   cp      r,r
 283 000001rdddddrrrr   cpc     r,r
 284 000100rdddddrrrr   cpse    r,r
 285 001001rdddddrrrr   eor     r,r
 286 001011rdddddrrrr   mov     r,r
 287 100111rdddddrrrr   mul     r,r
 288 001010rdddddrrrr   or      r,r
 289 000010rdddddrrrr   sbc     r,r
 290 000110rdddddrrrr   sub     r,r
 291 001001rdddddrrrr   clr     r
 292 000011rdddddrrrr   lsl     r
 293 000111rdddddrrrr   rol     r
 294 001000rdddddrrrr   tst     r
 295 0111KKKKddddKKKK   andi    d,M
 296 0111KKKKddddKKKK   cbr     d,n
 297 1110KKKKddddKKKK   ldi     d,M
 298 11101111dddd1111   ser     d
 299 0110KKKKddddKKKK   ori     d,M
 300 0110KKKKddddKKKK   sbr     d,M
 301 0011KKKKddddKKKK   cpi     d,M
 302 0100KKKKddddKKKK   sbci    d,M
 303 0101KKKKddddKKKK   subi    d,M
 304 1111110rrrrr0sss   sbrc    r,s
 305 1111111rrrrr0sss   sbrs    r,s
 306 1111100ddddd0sss   bld     r,s
 307 1111101ddddd0sss   bst     r,s
 308 10110PPdddddPPPP   in      r,P
 309 10111PPrrrrrPPPP   out     P,r
 310 10010110KKddKKKK   adiw    w,K
 311 10010111KKddKKKK   sbiw    w,K
 312 10011000pppppsss   cbi     p,s
 313 10011010pppppsss   sbi     p,s
 314 10011001pppppsss   sbic    p,s
 315 10011011pppppsss   sbis    p,s
 316 111101lllllll000   brcc    l
 317 111100lllllll000   brcs    l
 318 111100lllllll001   breq    l
 319 111101lllllll100   brge    l
 320 111101lllllll101   brhc    l
 321 111100lllllll101   brhs    l
 322 111101lllllll111   brid    l
 323 111100lllllll111   brie    l
 324 111100lllllll000   brlo    l
 325 111100lllllll100   brlt    l
 326 111100lllllll010   brmi    l
 327 111101lllllll001   brne    l
 328 111101lllllll010   brpl    l
 329 111101lllllll000   brsh    l
 330 111101lllllll110   brtc    l
 331 111100lllllll110   brts    l
 332 111101lllllll011   brvc    l
 333 111100lllllll011   brvs    l
 334 111101lllllllsss   brbc    s,l
 335 111100lllllllsss   brbs    s,l
 336 1101LLLLLLLLLLLL   rcall   L
 337 1100LLLLLLLLLLLL   rjmp    L
 338 1001010hhhhh111h   call    h
 339 1001010hhhhh110h   jmp     h
 340 1001010rrrrr0101   asr     r
 341 1001010rrrrr0000   com     r
 342 1001010rrrrr1010   dec     r
 343 1001010rrrrr0011   inc     r
 344 1001010rrrrr0110   lsr     r
 345 1001010rrrrr0001   neg     r
 346 1001000rrrrr1111   pop     r
 347 1001001rrrrr1111   push    r
 348 1001010rrrrr0111   ror     r
 349 1001010rrrrr0010   swap    r
 350 00000001ddddrrrr   movw    v,v
 351 00000010ddddrrrr   muls    d,d
 352 000000110ddd0rrr   mulsu   a,a
 353 000000110ddd1rrr   fmul    a,a
 354 000000111ddd0rrr   fmuls   a,a
 355 000000111ddd1rrr   fmulsu  a,a
 356 1001001ddddd0000   sts     i,r
 357 1001000ddddd0000   lds     r,i
 358 10o0oo0dddddbooo   ldd     r,b
 359 100!000dddddee-+   ld      r,e
 360 10o0oo1rrrrrbooo   std     b,r
 361 100!001rrrrree-+   st      e,r
 362 1001010100011001   eicall
 363 1001010000011001   eijmp
 364 @end smallexample