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
  49 Instruction set avr4 is for the enhanced AVR core with up to 8K program
  50 memory space (MCU types: atmega48, atmega48p,atmega8, atmega88, atmega88p,
  51 atmega8515, atmega8535, atmega8hva, at90pwm1, at90pwm2, at90pwm2b,
  52 at90pwm3, at90pwm3b).
  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, atmega168p, atmega169,
  57 atmega169p, atmega32, atmega323, atmega324p, atmega325, atmega325p,
  58 atmega328p, atmega329, atmega329p, atmega3250, atmega3250p, atmega3290,
  59 atmega3290p, atmega406, atmega64, atmega640, atmega644, atmega644p,
  60 atmega128, atmega1280, atmega1281, atmega1284p, atmega645, atmega649,
  61 atmega6450, atmega6490, atmega16hva, at90can32, at90can64, at90can128,
  62 at90pwm216, at90pwm316,at90usb82, at90usb162, at90usb646, at90usb647,
  63 at90usb1286, at90usb1287, at94k).
  64
  65 Instruction set avr6 is for the enhanced AVR core with 256K program
  66 memory space (MCU types: atmega2560, atmega2561).
  67
  68 @cindex @code{-mall-opcodes} command line option, AVR
  69 @item -mall-opcodes
  70 Accept all AVR opcodes, even if not supported by @code{-mmcu}.
  71
  72 @cindex @code{-mno-skip-bug} command line option, AVR
  73 @item -mno-skip-bug
  74 This option disable warnings for skipping two-word instructions.
  75
  76 @cindex @code{-mno-wrap} command line option, AVR
  77 @item -mno-wrap
  78 This option reject @code{rjmp/rcall} instructions with 8K wrap-around.
  79
  80 @end table
  81
  82
  83 @node AVR Syntax
  84 @section Syntax
  85 @menu
  86 * AVR-Chars::                Special Characters
  87 * AVR-Regs::                 Register Names
  88 * AVR-Modifiers::            Relocatable Expression Modifiers
  89 @end menu
  90
  91 @node AVR-Chars
  92 @subsection Special Characters
  93
  94 @cindex line comment character, AVR
  95 @cindex AVR line comment character
  96
  97 The presence of a @samp{;} on a line indicates the start of a comment
  98 that extends to the end of the current line.  If a @samp{#} appears as
  99 the first character of a line, the whole line is treated as a comment.
 100
 101 @cindex line separator, AVR
 102 @cindex statement separator, AVR
 103 @cindex AVR line separator
 104
 105 The @samp{$} character can be used instead of a newline to separate
 106 statements.
 107
 108 @node AVR-Regs
 109 @subsection Register Names
 110
 111 @cindex AVR register names
 112 @cindex register names, AVR
 113
 114 The AVR has 32 x 8-bit general purpose working registers @samp{r0},
 115 @samp{r1}, ... @samp{r31}.
 116 Six of the 32 registers can be used as three 16-bit indirect address
 117 register pointers for Data Space addressing. One of the these address
 118 pointers can also be used as an address pointer for look up tables in
 119 Flash program memory. These added function registers are the 16-bit
 120 @samp{X}, @samp{Y} and @samp{Z} - registers.
 121
 122 @smallexample
 123 X = @r{r26:r27}
 124 Y = @r{r28:r29}
 125 Z = @r{r30:r31}
 126 @end smallexample
 127
 128 @node AVR-Modifiers
 129 @subsection Relocatable Expression Modifiers
 130
 131 @cindex AVR modifiers
 132 @cindex syntax, AVR
 133
 134 The assembler supports several modifiers when using relocatable addresses
 135 in AVR instruction operands.  The general syntax is the following:
 136
 137 @smallexample
 138 modifier(relocatable-expression)
 139 @end smallexample
 140
 141 @table @code
 142 @cindex symbol modifiers
 143
 144 @item lo8
 145
 146 This modifier allows you to use bits 0 through 7 of
 147 an address expression as 8 bit relocatable expression.
 148
 149 @item hi8
 150
 151 This modifier allows you to use bits 7 through 15 of an address expression
 152 as 8 bit relocatable expression.  This is useful with, for example, the
 153 AVR @samp{ldi} instruction and @samp{lo8} modifier.
 154
 155 For example
 156
 157 @smallexample
 158 ldi r26, lo8(sym+10)
 159 ldi r27, hi8(sym+10)
 160 @end smallexample
 161
 162 @item hh8
 163
 164 This modifier allows you to use bits 16 through 23 of
 165 an address expression as 8 bit relocatable expression.
 166 Also, can be useful for loading 32 bit constants.
 167
 168 @item hlo8
 169
 170 Synonym of @samp{hh8}.
 171
 172 @item hhi8
 173
 174 This modifier allows you to use bits 24 through 31 of
 175 an expression as 8 bit expression. This is useful with, for example, the
 176 AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
 177 @samp{hhi8}, modifier.
 178
 179 For example
 180
 181 @smallexample
 182 ldi r26, lo8(285774925)
 183 ldi r27, hi8(285774925)
 184 ldi r28, hlo8(285774925)
 185 ldi r29, hhi8(285774925)
 186 ; r29,r28,r27,r26 = 285774925
 187 @end smallexample
 188
 189 @item pm_lo8
 190
 191 This modifier allows you to use bits 0 through 7 of
 192 an address expression as 8 bit relocatable expression.
 193 This modifier useful for addressing data or code from
 194 Flash/Program memory. The using of @samp{pm_lo8} similar
 195 to @samp{lo8}.
 196
 197 @item pm_hi8
 198
 199 This modifier allows you to use bits 8 through 15 of
 200 an address expression as 8 bit relocatable expression.
 201 This modifier useful for addressing data or code from
 202 Flash/Program memory.
 203
 204 @item pm_hh8
 205
 206 This modifier allows you to use bits 15 through 23 of
 207 an address expression as 8 bit relocatable expression.
 208 This modifier useful for addressing data or code from
 209 Flash/Program memory.
 210
 211 @end table
 212
 213 @node AVR Opcodes
 214 @section Opcodes
 215
 216 @cindex AVR opcode summary
 217 @cindex opcode summary, AVR
 218 @cindex mnemonics, AVR
 219 @cindex instruction summary, AVR
 220 For detailed information on the AVR machine instruction set, see
 221 @url{www.atmel.com/products/AVR}.
 222
 223 @code{@value{AS}} implements all the standard AVR opcodes.
 224 The following table summarizes the AVR opcodes, and their arguments.
 225
 226 @smallexample
 227 @i{Legend:}
 228    r   @r{any register}
 229    d   @r{`ldi' register (r16-r31)}
 230    v   @r{`movw' even register (r0, r2, ..., r28, r30)}
 231    a   @r{`fmul' register (r16-r23)}
 232    w   @r{`adiw' register (r24,r26,r28,r30)}
 233    e   @r{pointer registers (X,Y,Z)}
 234    b   @r{base pointer register and displacement ([YZ]+disp)}
 235    z   @r{Z pointer register (for [e]lpm Rd,Z[+])}
 236    M   @r{immediate value from 0 to 255}
 237    n   @r{immediate value from 0 to 255 ( n = ~M ). Relocation impossible}
 238    s   @r{immediate value from 0 to 7}
 239    P   @r{Port address value from 0 to 63. (in, out)}
 240    p   @r{Port address value from 0 to 31. (cbi, sbi, sbic, sbis)}
 241    K   @r{immediate value from 0 to 63 (used in `adiw', `sbiw')}
 242    i   @r{immediate value}
 243    l   @r{signed pc relative offset from -64 to 63}
 244    L   @r{signed pc relative offset from -2048 to 2047}
 245    h   @r{absolute code address (call, jmp)}
 246    S   @r{immediate value from 0 to 7 (S = s << 4)}
 247    ?   @r{use this opcode entry if no parameters, else use next opcode entry}
 248
 249 1001010010001000   clc
 250 1001010011011000   clh
 251 1001010011111000   cli
 252 1001010010101000   cln
 253 1001010011001000   cls
 254 1001010011101000   clt
 255 1001010010111000   clv
 256 1001010010011000   clz
 257 1001010000001000   sec
 258 1001010001011000   seh
 259 1001010001111000   sei
 260 1001010000101000   sen
 261 1001010001001000   ses
 262 1001010001101000   set
 263 1001010000111000   sev
 264 1001010000011000   sez
 265 100101001SSS1000   bclr    S
 266 100101000SSS1000   bset    S
 267 1001010100001001   icall
 268 1001010000001001   ijmp
 269 1001010111001000   lpm     ?
 270 1001000ddddd010+   lpm     r,z
 271 1001010111011000   elpm    ?
 272 1001000ddddd011+   elpm    r,z
 273 0000000000000000   nop
 274 1001010100001000   ret
 275 1001010100011000   reti
 276 1001010110001000   sleep
 277 1001010110011000   break
 278 1001010110101000   wdr
 279 1001010111101000   spm
 280 000111rdddddrrrr   adc     r,r
 281 000011rdddddrrrr   add     r,r
 282 001000rdddddrrrr   and     r,r
 283 000101rdddddrrrr   cp      r,r
 284 000001rdddddrrrr   cpc     r,r
 285 000100rdddddrrrr   cpse    r,r
 286 001001rdddddrrrr   eor     r,r
 287 001011rdddddrrrr   mov     r,r
 288 100111rdddddrrrr   mul     r,r
 289 001010rdddddrrrr   or      r,r
 290 000010rdddddrrrr   sbc     r,r
 291 000110rdddddrrrr   sub     r,r
 292 001001rdddddrrrr   clr     r
 293 000011rdddddrrrr   lsl     r
 294 000111rdddddrrrr   rol     r
 295 001000rdddddrrrr   tst     r
 296 0111KKKKddddKKKK   andi    d,M
 297 0111KKKKddddKKKK   cbr     d,n
 298 1110KKKKddddKKKK   ldi     d,M
 299 11101111dddd1111   ser     d
 300 0110KKKKddddKKKK   ori     d,M
 301 0110KKKKddddKKKK   sbr     d,M
 302 0011KKKKddddKKKK   cpi     d,M
 303 0100KKKKddddKKKK   sbci    d,M
 304 0101KKKKddddKKKK   subi    d,M
 305 1111110rrrrr0sss   sbrc    r,s
 306 1111111rrrrr0sss   sbrs    r,s
 307 1111100ddddd0sss   bld     r,s
 308 1111101ddddd0sss   bst     r,s
 309 10110PPdddddPPPP   in      r,P
 310 10111PPrrrrrPPPP   out     P,r
 311 10010110KKddKKKK   adiw    w,K
 312 10010111KKddKKKK   sbiw    w,K
 313 10011000pppppsss   cbi     p,s
 314 10011010pppppsss   sbi     p,s
 315 10011001pppppsss   sbic    p,s
 316 10011011pppppsss   sbis    p,s
 317 111101lllllll000   brcc    l
 318 111100lllllll000   brcs    l
 319 111100lllllll001   breq    l
 320 111101lllllll100   brge    l
 321 111101lllllll101   brhc    l
 322 111100lllllll101   brhs    l
 323 111101lllllll111   brid    l
 324 111100lllllll111   brie    l
 325 111100lllllll000   brlo    l
 326 111100lllllll100   brlt    l
 327 111100lllllll010   brmi    l
 328 111101lllllll001   brne    l
 329 111101lllllll010   brpl    l
 330 111101lllllll000   brsh    l
 331 111101lllllll110   brtc    l
 332 111100lllllll110   brts    l
 333 111101lllllll011   brvc    l
 334 111100lllllll011   brvs    l
 335 111101lllllllsss   brbc    s,l
 336 111100lllllllsss   brbs    s,l
 337 1101LLLLLLLLLLLL   rcall   L
 338 1100LLLLLLLLLLLL   rjmp    L
 339 1001010hhhhh111h   call    h
 340 1001010hhhhh110h   jmp     h
 341 1001010rrrrr0101   asr     r
 342 1001010rrrrr0000   com     r
 343 1001010rrrrr1010   dec     r
 344 1001010rrrrr0011   inc     r
 345 1001010rrrrr0110   lsr     r
 346 1001010rrrrr0001   neg     r
 347 1001000rrrrr1111   pop     r
 348 1001001rrrrr1111   push    r
 349 1001010rrrrr0111   ror     r
 350 1001010rrrrr0010   swap    r
 351 00000001ddddrrrr   movw    v,v
 352 00000010ddddrrrr   muls    d,d
 353 000000110ddd0rrr   mulsu   a,a
 354 000000110ddd1rrr   fmul    a,a
 355 000000111ddd0rrr   fmuls   a,a
 356 000000111ddd1rrr   fmulsu  a,a
 357 1001001ddddd0000   sts     i,r
 358 1001000ddddd0000   lds     r,i
 359 10o0oo0dddddbooo   ldd     r,b
 360 100!000dddddee-+   ld      r,e
 361 10o0oo1rrrrrbooo   std     b,r
 362 100!001rrrrree-+   st      e,r
 363 1001010100011001   eicall
 364 1001010000011001   eijmp
 365 @end smallexample