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,
  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, attiny43u, attiny48, attiny88).
  45
  46 Instruction set avr3 is for the classic AVR core with up to 128K program
  47 memory space (MCU types: atmega103, at43usb320, at43usb355, at76c711,
  48 at90usb82, at90usb162, attiny167).
  49
  50 Instruction set avr4 is for the enhanced AVR core with up to 8K program
  51 memory space (MCU types: atmega48, atmega48p,atmega8, atmega88, atmega88p,
  52 atmega8515, atmega8535, atmega8hva, at90pwm1, at90pwm2, at90pwm2b,
  53 at90pwm3, at90pwm3b).
  54
  55 Instruction set avr5 is for the enhanced AVR core with up to 128K program
  56 memory space (MCU types: atmega16, atmega161, atmega162, atmega163,
  57 atmega164p, atmega165, atmega165p, atmega168, atmega168p, atmega169,
  58 atmega169p, atmega32, atmega323, atmega324p, atmega325, atmega325p,
  59 atmega328p, atmega329, atmega329p, atmega3250, atmega3250p, atmega3290,
  60 atmega3290p, atmega32hvb, atmega406, atmega64, atmega640, atmega644,
  61 atmega644p, atmega128, atmega1280, atmega1281, atmega1284p, atmega645,
  62 atmega649, atmega6450, atmega6490, atmega16hva, at90can32, at90can64,
  63 at90can128, at90pwm216, at90pwm316, atmega32c1, atmega32m1, atmega32u4,
  64 at90usb646, at90usb647, at90usb1286, at90usb1287, at94k).
  65
  66 Instruction set avr6 is for the enhanced AVR core with 256K program
  67 memory space (MCU types: atmega2560, atmega2561).
  68
  69 @cindex @code{-mall-opcodes} command line option, AVR
  70 @item -mall-opcodes
  71 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  72
  73 @cindex @code{-mno-skip-bug} command line option, AVR
  74 @item -mno-skip-bug
  75 This option disable warnings for skipping two-word instructions.
  76
  77 @cindex @code{-mno-wrap} command line option, AVR
  78 @item -mno-wrap
  79 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  80
  81 @end table
  82
  83
  84 @node AVR Syntax
  85 @section Syntax
  86 @menu
  87 * AVR-Chars::                Special Characters
  88 * AVR-Regs::                 Register Names
  89 * AVR-Modifiers::            Relocatable Expression Modifiers
  90 @end menu
  91
  92 @node AVR-Chars
  93 @subsection Special Characters
  94
  95 @cindex line comment character, AVR
  96 @cindex AVR line comment character
  97
  98 The presence of a @samp{;} on a line indicates the start of a comment
  99 that extends to the end of the current line.  If a @samp{#} appears as
 100 the first character of a line, the whole line is treated as a comment.
 101
 102 @cindex line separator, AVR
 103 @cindex statement separator, AVR
 104 @cindex AVR line separator
 105
 106 The @samp{$} character can be used instead of a newline to separate
 107 statements.
 108
 109 @node AVR-Regs
 110 @subsection Register Names
 111
 112 @cindex AVR register names
 113 @cindex register names, AVR
 114
 115 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 116 @samp{r1}, ... @samp{r31}.
 117 Six of the 32 registers can be used as three 16-bit indirect address
 118 register pointers for Data Space addressing. One of the these address
 119 pointers can also be used as an address pointer for look up tables in
 120 Flash program memory. These added function registers are the 16-bit
 121 @samp{X}, @samp{Y} and @samp{Z} - registers.
 122
 123 @smallexample
 124 X = @r{r26:r27}
 125 Y = @r{r28:r29}
 126 Z = @r{r30:r31}
 127 @end smallexample
 128
 129 @node AVR-Modifiers
 130 @subsection Relocatable Expression Modifiers
 131
 132 @cindex AVR modifiers
 133 @cindex syntax, AVR
 134
 135 The assembler supports several modifiers when using relocatable addresses
 136 in AVR instruction operands.  The general syntax is the following:
 137
 138 @smallexample
 139 modifier(relocatable-expression)
 140 @end smallexample
 141
 142 @table @code
 143 @cindex symbol modifiers
 144
 145 @item lo8
 146
 147 This modifier allows you to use bits 0 through 7 of
 148 an address expression as 8 bit relocatable expression.
 149
 150 @item hi8
 151
 152 This modifier allows you to use bits 7 through 15 of an address expression
 153 as 8 bit relocatable expression.  This is useful with, for example, the
 154 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 155
 156 For example
 157
 158 @smallexample
 159 ldi r26, lo8(sym+10)
 160 ldi r27, hi8(sym+10)
 161 @end smallexample
 162
 163 @item hh8
 164
 165 This modifier allows you to use bits 16 through 23 of
 166 an address expression as 8 bit relocatable expression.
 167 Also, can be useful for loading 32 bit constants.
 168
 169 @item hlo8
 170
 171 Synonym of @samp{hh8}.
 172
 173 @item hhi8
 174
 175 This modifier allows you to use bits 24 through 31 of
 176 an expression as 8 bit expression. This is useful with, for example, the
 177 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 178 @samp{hhi8}, modifier.
 179
 180 For example
 181
 182 @smallexample
 183 ldi r26, lo8(285774925)
 184 ldi r27, hi8(285774925)
 185 ldi r28, hlo8(285774925)
 186 ldi r29, hhi8(285774925)
 187 ; r29,r28,r27,r26 = 285774925
 188 @end smallexample
 189
 190 @item pm_lo8
 191
 192 This modifier allows you to use bits 0 through 7 of
 193 an address expression as 8 bit relocatable expression.
 194 This modifier useful for addressing data or code from
 195 Flash/Program memory. The using of @samp{pm_lo8} similar
 196 to @samp{lo8}.
 197
 198 @item pm_hi8
 199
 200 This modifier allows you to use bits 8 through 15 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 @item pm_hh8
 206
 207 This modifier allows you to use bits 15 through 23 of
 208 an address expression as 8 bit relocatable expression.
 209 This modifier useful for addressing data or code from
 210 Flash/Program memory.
 211
 212 @end table
 213
 214 @node AVR Opcodes
 215 @section Opcodes
 216
 217 @cindex AVR opcode summary
 218 @cindex opcode summary, AVR
 219 @cindex mnemonics, AVR
 220 @cindex instruction summary, AVR
 221 For detailed information on the AVR machine instruction set, see
 222 @url{www.atmel.com/products/AVR}.
 223
 224 @code{@value{AS}} implements all the standard AVR opcodes.
 225 The following table summarizes the AVR opcodes, and their arguments.
 226
 227 @smallexample
 228 @i{Legend:}
 229    r   @r{any register}
 230    d   @r{`ldi' register (r16-r31)}
 231    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 232    a   @r{`fmul' register (r16-r23)}
 233    w   @r{`adiw' register (r24,r26,r28,r30)}
 234    e   @r{pointer registers (X,Y,Z)}
 235    b   @r{base pointer register and displacement ([YZ]+disp)}
 236    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 237    M   @r{immediate value from 0 to 255}
 238    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 239    s   @r{immediate value from 0 to 7}
 240    P   @r{Port address value from 0 to 63. (in, out)}
 241    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 242    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 243    i   @r{immediate value}
 244    l   @r{signed pc relative offset from -64 to 63}
 245    L   @r{signed pc relative offset from -2048 to 2047}
 246    h   @r{absolute code address (call, jmp)}
 247    S   @r{immediate value from 0 to 7 (S = s << 4)}
 248    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 249
 250 1001010010001000   clc
 251 1001010011011000   clh
 252 1001010011111000   cli
 253 1001010010101000   cln
 254 1001010011001000   cls
 255 1001010011101000   clt
 256 1001010010111000   clv
 257 1001010010011000   clz
 258 1001010000001000   sec
 259 1001010001011000   seh
 260 1001010001111000   sei
 261 1001010000101000   sen
 262 1001010001001000   ses
 263 1001010001101000   set
 264 1001010000111000   sev
 265 1001010000011000   sez
 266 100101001SSS1000   bclr    S
 267 100101000SSS1000   bset    S
 268 1001010100001001   icall
 269 1001010000001001   ijmp
 270 1001010111001000   lpm     ?
 271 1001000ddddd010+   lpm     r,z
 272 1001010111011000   elpm    ?
 273 1001000ddddd011+   elpm    r,z
 274 0000000000000000   nop
 275 1001010100001000   ret
 276 1001010100011000   reti
 277 1001010110001000   sleep
 278 1001010110011000   break
 279 1001010110101000   wdr
 280 1001010111101000   spm
 281 000111rdddddrrrr   adc     r,r
 282 000011rdddddrrrr   add     r,r
 283 001000rdddddrrrr   and     r,r
 284 000101rdddddrrrr   cp      r,r
 285 000001rdddddrrrr   cpc     r,r
 286 000100rdddddrrrr   cpse    r,r
 287 001001rdddddrrrr   eor     r,r
 288 001011rdddddrrrr   mov     r,r
 289 100111rdddddrrrr   mul     r,r
 290 001010rdddddrrrr   or      r,r
 291 000010rdddddrrrr   sbc     r,r
 292 000110rdddddrrrr   sub     r,r
 293 001001rdddddrrrr   clr     r
 294 000011rdddddrrrr   lsl     r
 295 000111rdddddrrrr   rol     r
 296 001000rdddddrrrr   tst     r
 297 0111KKKKddddKKKK   andi    d,M
 298 0111KKKKddddKKKK   cbr     d,n
 299 1110KKKKddddKKKK   ldi     d,M
 300 11101111dddd1111   ser     d
 301 0110KKKKddddKKKK   ori     d,M
 302 0110KKKKddddKKKK   sbr     d,M
 303 0011KKKKddddKKKK   cpi     d,M
 304 0100KKKKddddKKKK   sbci    d,M
 305 0101KKKKddddKKKK   subi    d,M
 306 1111110rrrrr0sss   sbrc    r,s
 307 1111111rrrrr0sss   sbrs    r,s
 308 1111100ddddd0sss   bld     r,s
 309 1111101ddddd0sss   bst     r,s
 310 10110PPdddddPPPP   in      r,P
 311 10111PPrrrrrPPPP   out     P,r
 312 10010110KKddKKKK   adiw    w,K
 313 10010111KKddKKKK   sbiw    w,K
 314 10011000pppppsss   cbi     p,s
 315 10011010pppppsss   sbi     p,s
 316 10011001pppppsss   sbic    p,s
 317 10011011pppppsss   sbis    p,s
 318 111101lllllll000   brcc    l
 319 111100lllllll000   brcs    l
 320 111100lllllll001   breq    l
 321 111101lllllll100   brge    l
 322 111101lllllll101   brhc    l
 323 111100lllllll101   brhs    l
 324 111101lllllll111   brid    l
 325 111100lllllll111   brie    l
 326 111100lllllll000   brlo    l
 327 111100lllllll100   brlt    l
 328 111100lllllll010   brmi    l
 329 111101lllllll001   brne    l
 330 111101lllllll010   brpl    l
 331 111101lllllll000   brsh    l
 332 111101lllllll110   brtc    l
 333 111100lllllll110   brts    l
 334 111101lllllll011   brvc    l
 335 111100lllllll011   brvs    l
 336 111101lllllllsss   brbc    s,l
 337 111100lllllllsss   brbs    s,l
 338 1101LLLLLLLLLLLL   rcall   L
 339 1100LLLLLLLLLLLL   rjmp    L
 340 1001010hhhhh111h   call    h
 341 1001010hhhhh110h   jmp     h
 342 1001010rrrrr0101   asr     r
 343 1001010rrrrr0000   com     r
 344 1001010rrrrr1010   dec     r
 345 1001010rrrrr0011   inc     r
 346 1001010rrrrr0110   lsr     r
 347 1001010rrrrr0001   neg     r
 348 1001000rrrrr1111   pop     r
 349 1001001rrrrr1111   push    r
 350 1001010rrrrr0111   ror     r
 351 1001010rrrrr0010   swap    r
 352 00000001ddddrrrr   movw    v,v
 353 00000010ddddrrrr   muls    d,d
 354 000000110ddd0rrr   mulsu   a,a
 355 000000110ddd1rrr   fmul    a,a
 356 000000111ddd0rrr   fmuls   a,a
 357 000000111ddd1rrr   fmulsu  a,a
 358 1001001ddddd0000   sts     i,r
 359 1001000ddddd0000   lds     r,i
 360 10o0oo0dddddbooo   ldd     r,b
 361 100!000dddddee-+   ld      r,e
 362 10o0oo1rrrrrbooo   std     b,r
 363 100!001rrrrree-+   st      e,r
 364 1001010100011001   eicall
 365 1001010000011001   eijmp
 366 @end smallexample