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, 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 atmega164, atmega165, atmega168, atmega169, atmega32, atmega323,
  57 atmega324, atmega325, atmega329, atmega3250, atmega3290, atmega406,
  58 atmega64, atmega640, atmega644, atmega128, atmega1280, atmega1281,
  59 atmega645, atmega649, atmega6450, atmega6490, at90can32, at90can64,
  60 at90can128, at90usb646, at90usb647, at90usb1286, at90usb1287, at94k).
  61
  62 @cindex @code{-mall-opcodes} command line option, AVR
  63 @item -mall-opcodes
  64 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  65
  66 @cindex @code{-mno-skip-bug} command line option, AVR
  67 @item -mno-skip-bug
  68 This option disable warnings for skipping two-word instructions.
  69
  70 @cindex @code{-mno-wrap} command line option, AVR
  71 @item -mno-wrap
  72 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  73
  74 @end table
  75
  76
  77 @node AVR Syntax
  78 @section Syntax
  79 @menu
  80 * AVR-Chars::                Special Characters
  81 * AVR-Regs::                 Register Names
  82 * AVR-Modifiers::            Relocatable Expression Modifiers
  83 @end menu
  84
  85 @node AVR-Chars
  86 @subsection Special Characters
  87
  88 @cindex line comment character, AVR
  89 @cindex AVR line comment character
  90
  91 The presence of a @samp{;} on a line indicates the start of a comment
  92 that extends to the end of the current line.  If a @samp{#} appears as
  93 the first character of a line, the whole line is treated as a comment.
  94
  95 @cindex line separator, AVR
  96 @cindex statement separator, AVR
  97 @cindex AVR line separator
  98
  99 The @samp{$} character can be used instead of a newline to separate
 100 statements.
 101
 102 @node AVR-Regs
 103 @subsection Register Names
 104
 105 @cindex AVR register names
 106 @cindex register names, AVR
 107
 108 The AVR has 32 x 8-bit general purpouse working registers @samp{r0},
 109 @samp{r1}, ... @samp{r31}.
 110 Six of the 32 registers can be used as three 16-bit indirect address
 111 register pointers for Data Space addressing. One of the these address
 112 pointers can also be used as an address pointer for look up tables in
 113 Flash program memory. These added function registers are the 16-bit
 114 @samp{X}, @samp{Y} and @samp{Z} - registers.
 115
 116 @smallexample
 117 X = @r{r26:r27}
 118 Y = @r{r28:r29}
 119 Z = @r{r30:r31}
 120 @end smallexample
 121
 122 @node AVR-Modifiers
 123 @subsection Relocatable Expression Modifiers
 124
 125 @cindex AVR modifiers
 126 @cindex syntax, AVR
 127
 128 The assembler supports several modifiers when using relocatable addresses
 129 in AVR instruction operands.  The general syntax is the following:
 130
 131 @smallexample
 132 modifier(relocatable-expression)
 133 @end smallexample
 134
 135 @table @code
 136 @cindex symbol modifiers
 137
 138 @item lo8
 139
 140 This modifier allows you to use bits 0 through 7 of
 141 an address expression as 8 bit relocatable expression.
 142
 143 @item hi8
 144
 145 This modifier allows you to use bits 7 through 15 of an address expression
 146 as 8 bit relocatable expression.  This is useful with, for example, the
 147 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 148
 149 For example
 150
 151 @smallexample
 152 ldi r26, lo8(sym+10)
 153 ldi r27, hi8(sym+10)
 154 @end smallexample
 155
 156 @item hh8
 157
 158 This modifier allows you to use bits 16 through 23 of
 159 an address expression as 8 bit relocatable expression.
 160 Also, can be useful for loading 32 bit constants.
 161
 162 @item hlo8
 163
 164 Synonym of @samp{hh8}.
 165
 166 @item hhi8
 167
 168 This modifier allows you to use bits 24 through 31 of
 169 an expression as 8 bit expression. This is useful with, for example, the
 170 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 171 @samp{hhi8}, modifier.
 172
 173 For example
 174
 175 @smallexample
 176 ldi r26, lo8(285774925)
 177 ldi r27, hi8(285774925)
 178 ldi r28, hlo8(285774925)
 179 ldi r29, hhi8(285774925)
 180 ; r29,r28,r27,r26 = 285774925
 181 @end smallexample
 182
 183 @item pm_lo8
 184
 185 This modifier allows you to use bits 0 through 7 of
 186 an address expression as 8 bit relocatable expression.
 187 This modifier useful for addressing data or code from
 188 Flash/Program memory. The using of @samp{pm_lo8} similar
 189 to @samp{lo8}.
 190
 191 @item pm_hi8
 192
 193 This modifier allows you to use bits 8 through 15 of
 194 an address expression as 8 bit relocatable expression.
 195 This modifier useful for addressing data or code from
 196 Flash/Program memory.
 197
 198 @item pm_hh8
 199
 200 This modifier allows you to use bits 15 through 23 of
 201 an address expression as 8 bit relocatable expression.
 202 This modifier useful for addressing data or code from
 203 Flash/Program memory.
 204
 205 @end table
 206
 207 @node AVR Opcodes
 208 @section Opcodes
 209
 210 @cindex AVR opcode summary
 211 @cindex opcode summary, AVR
 212 @cindex mnemonics, AVR
 213 @cindex instruction summary, AVR
 214 For detailed information on the AVR machine instruction set, see
 215 @url{www.atmel.com/products/AVR}.
 216
 217 @code{@value{AS}} implements all the standard AVR opcodes.
 218 The following table summarizes the AVR opcodes, and their arguments.
 219
 220 @smallexample
 221 @i{Legend:}
 222    r   @r{any register}
 223    d   @r{`ldi' register (r16-r31)}
 224    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 225    a   @r{`fmul' register (r16-r23)}
 226    w   @r{`adiw' register (r24,r26,r28,r30)}
 227    e   @r{pointer registers (X,Y,Z)}
 228    b   @r{base pointer register and displacement ([YZ]+disp)}
 229    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 230    M   @r{immediate value from 0 to 255}
 231    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 232    s   @r{immediate value from 0 to 7}
 233    P   @r{Port address value from 0 to 63. (in, out)}
 234    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 235    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 236    i   @r{immediate value}
 237    l   @r{signed pc relative offset from -64 to 63}
 238    L   @r{signed pc relative offset from -2048 to 2047}
 239    h   @r{absolute code address (call, jmp)}
 240    S   @r{immediate value from 0 to 7 (S = s << 4)}
 241    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 242
 243 1001010010001000   clc
 244 1001010011011000   clh
 245 1001010011111000   cli
 246 1001010010101000   cln
 247 1001010011001000   cls
 248 1001010011101000   clt
 249 1001010010111000   clv
 250 1001010010011000   clz
 251 1001010000001000   sec
 252 1001010001011000   seh
 253 1001010001111000   sei
 254 1001010000101000   sen
 255 1001010001001000   ses
 256 1001010001101000   set
 257 1001010000111000   sev
 258 1001010000011000   sez
 259 100101001SSS1000   bclr    S
 260 100101000SSS1000   bset    S
 261 1001010100001001   icall
 262 1001010000001001   ijmp
 263 1001010111001000   lpm     ?
 264 1001000ddddd010+   lpm     r,z
 265 1001010111011000   elpm    ?
 266 1001000ddddd011+   elpm    r,z
 267 0000000000000000   nop
 268 1001010100001000   ret
 269 1001010100011000   reti
 270 1001010110001000   sleep
 271 1001010110011000   break
 272 1001010110101000   wdr
 273 1001010111101000   spm
 274 000111rdddddrrrr   adc     r,r
 275 000011rdddddrrrr   add     r,r
 276 001000rdddddrrrr   and     r,r
 277 000101rdddddrrrr   cp      r,r
 278 000001rdddddrrrr   cpc     r,r
 279 000100rdddddrrrr   cpse    r,r
 280 001001rdddddrrrr   eor     r,r
 281 001011rdddddrrrr   mov     r,r
 282 100111rdddddrrrr   mul     r,r
 283 001010rdddddrrrr   or      r,r
 284 000010rdddddrrrr   sbc     r,r
 285 000110rdddddrrrr   sub     r,r
 286 001001rdddddrrrr   clr     r
 287 000011rdddddrrrr   lsl     r
 288 000111rdddddrrrr   rol     r
 289 001000rdddddrrrr   tst     r
 290 0111KKKKddddKKKK   andi    d,M
 291 0111KKKKddddKKKK   cbr     d,n
 292 1110KKKKddddKKKK   ldi     d,M
 293 11101111dddd1111   ser     d
 294 0110KKKKddddKKKK   ori     d,M
 295 0110KKKKddddKKKK   sbr     d,M
 296 0011KKKKddddKKKK   cpi     d,M
 297 0100KKKKddddKKKK   sbci    d,M
 298 0101KKKKddddKKKK   subi    d,M
 299 1111110rrrrr0sss   sbrc    r,s
 300 1111111rrrrr0sss   sbrs    r,s
 301 1111100ddddd0sss   bld     r,s
 302 1111101ddddd0sss   bst     r,s
 303 10110PPdddddPPPP   in      r,P
 304 10111PPrrrrrPPPP   out     P,r
 305 10010110KKddKKKK   adiw    w,K
 306 10010111KKddKKKK   sbiw    w,K
 307 10011000pppppsss   cbi     p,s
 308 10011010pppppsss   sbi     p,s
 309 10011001pppppsss   sbic    p,s
 310 10011011pppppsss   sbis    p,s
 311 111101lllllll000   brcc    l
 312 111100lllllll000   brcs    l
 313 111100lllllll001   breq    l
 314 111101lllllll100   brge    l
 315 111101lllllll101   brhc    l
 316 111100lllllll101   brhs    l
 317 111101lllllll111   brid    l
 318 111100lllllll111   brie    l
 319 111100lllllll000   brlo    l
 320 111100lllllll100   brlt    l
 321 111100lllllll010   brmi    l
 322 111101lllllll001   brne    l
 323 111101lllllll010   brpl    l
 324 111101lllllll000   brsh    l
 325 111101lllllll110   brtc    l
 326 111100lllllll110   brts    l
 327 111101lllllll011   brvc    l
 328 111100lllllll011   brvs    l
 329 111101lllllllsss   brbc    s,l
 330 111100lllllllsss   brbs    s,l
 331 1101LLLLLLLLLLLL   rcall   L
 332 1100LLLLLLLLLLLL   rjmp    L
 333 1001010hhhhh111h   call    h
 334 1001010hhhhh110h   jmp     h
 335 1001010rrrrr0101   asr     r
 336 1001010rrrrr0000   com     r
 337 1001010rrrrr1010   dec     r
 338 1001010rrrrr0011   inc     r
 339 1001010rrrrr0110   lsr     r
 340 1001010rrrrr0001   neg     r
 341 1001000rrrrr1111   pop     r
 342 1001001rrrrr1111   push    r
 343 1001010rrrrr0111   ror     r
 344 1001010rrrrr0010   swap    r
 345 00000001ddddrrrr   movw    v,v
 346 00000010ddddrrrr   muls    d,d
 347 000000110ddd0rrr   mulsu   a,a
 348 000000110ddd1rrr   fmul    a,a
 349 000000111ddd0rrr   fmuls   a,a
 350 000000111ddd1rrr   fmulsu  a,a
 351 1001001ddddd0000   sts     i,r
 352 1001000ddddd0000   lds     r,i
 353 10o0oo0dddddbooo   ldd     r,b
 354 100!000dddddee-+   ld      r,e
 355 10o0oo1rrrrrbooo   std     b,r
 356 100!001rrrrree-+   st      e,r
 357 1001010100011001   eicall
 358 1001010000011001   eijmp
 359 @end smallexample