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<TeXmacs|1.0.7.19>
<style|generic>
<\body>
<doc-data|<doc-title|Sp�cification processeur>|<doc-subtitle|Projet Syst�me
Digital 2013>|<doc-author|<author-data|<author-name|A.Auvolat, E.Enguehard,
J.Laurent>>>>
Nous proposons ici une sp�cification pour un processeur minimaliste 16 bit
RISC.
<section|Registres>
La machine dispose de 8 registres \S g�n�raux \T, tous de taille 16 bits :
\;
<\itemize>
<item>0. Registre <verbatim|Z> ou z�ro (valant tout le temps 0...)
<item>1. Registre <verbatim|A>
<item>2. Registre <verbatim|B>
<item>3. Registre <verbatim|C>
<item>4. Registre <verbatim|D>
<item>5. Registre <verbatim|E>, �crit par certaines instructions
(multiplication, division...) et utilis� pr�f�rentiellement comme
registre temporaire pour certaines instructions compos�es
<item>6. Registre <verbatim|F>, ou <verbatim|RA> (return adresse), �crit
par l'instruction <verbatim|jal>
<item>7. Registre <verbatim|G>, ou <verbatim|SP> (stack pointer), utilis�
par les instructions <verbatim|pop> et <verbatim|push>
</itemize>
Ces 8 registres sont tous manipulables par les instructions prenant un
registre comme argument. De plus, le processeur dispose d'un registre
manipulable uniquement par certaines instructions sp�cifiques, le registre
<verbatim|PC> (program counter : contient l'adresse de l'instruction
courante).
Les num�ros de registres sont donc cod�s sur 3 bits.
<section|M�moire>
La m�moire est adress�e sur 16 bits et les mots m�moire font 8 bits, il y a
donc 64ko disponnibles.
Le CPU est little-endian (le mot 0x1234 est cod� 34 puis 12)
On d�finit plusieurs zones de m�moire :
<big-table|<tabular*|<tformat|<table|<row|<cell|0x0000 - 0x3FFF>|<cell|ROM
pour programme utilisateur>>|<row|<cell|0x4000 - 0x7FFF>|<cell|MMIO (seuls
quelques octets sont utilis�s)>>|<row|<cell|0x8000 - 0xFFFF>|<cell|RAM pour
programme utilisateur>>>>>|Memory map>
Les bits suivants sont utilis�s pour la MMIO :
<big-table|<tabular*|<tformat|<table|<row|<cell|>>>>><tabular*|<tformat|<table|<row|<cell|byte
at 0x4000>|<cell|Clock ticker (incremented every tick, reset on
read)>>|<row|<cell|byte at 0x4100>|<cell|Serial input (set when byte
received, reset on read)>>|<row|<cell|byte at 0x4102>|<cell|Serial output
(sends byte immediately on write)>>>>>|Addresses MMIO>
<section|Jeu d'instruction>
Les instructions sont cod�es sur 16 bits. Les tableaux suivants montrent
les instructions avec les bits de poids forts � gauche et les bits de poids
faibles � droite (convention contraire � celle exprim�e dans le
<verbatim|README>).
<subsection|Types d'instructions>
<paragraph|Format de base><tabular*|<tformat|<cwith|2|2|1|-1|cell-lborder|1px>|<cwith|2|2|1|-1|cell-bborder|1px>|<cwith|2|2|1|-1|cell-tborder|1px>|<cwith|2|2|3|3|cell-rborder|1px>|<table|<row|<cell|5
bits>|<cell|3 bits>|<cell|8 bits>>|<row|<cell|<math|I>>|<cell|<math|R>>|<cell|<math|\<ldots\>>>>|<row|<cell|poids
forts>|<cell|>|<cell|poids faibles>>>>>
<paragraph|Format <math|R>><tabular*|<tformat|<cwith|2|2|1|-1|cell-lborder|1px>|<cwith|2|2|1|-1|cell-bborder|1px>|<cwith|2|2|1|-1|cell-tborder|1px>|<cwith|2|2|3|3|cell-rborder|1px>|<cwith|2|2|5|5|cell-rborder|1px>|<table|<row|<cell|5
bits>|<cell|3 bits>|<cell|3 bits>|<cell|3 bits>|<cell|2
bits>>|<row|<cell|<math|I>>|<cell|<math|R>>|<cell|<math|R<rsub|A>>>|<cell|<math|R<rsub|B>>>|<cell|<math|f>>>>>>
<paragraph|Format <math|I>><tabular*|<tformat|<cwith|2|2|1|-1|cell-lborder|1px>|<cwith|2|2|1|-1|cell-bborder|1px>|<cwith|2|2|1|-1|cell-tborder|1px>|<cwith|2|2|3|3|cell-rborder|1px>|<table|<row|<cell|5
bits>|<cell|3 bits>|<cell|8 bits>>|<row|<cell|<math|I>>|<cell|<math|R>>|<cell|<math|d>>>>>>
<paragraph|Format K><tabular*|<tformat|<cwith|2|2|1|-1|cell-lborder|1px>|<cwith|2|2|1|-1|cell-bborder|1px>|<cwith|2|2|1|-1|cell-tborder|1px>|<cwith|2|2|3|3|cell-rborder|1px>|<cwith|2|2|4|4|cell-rborder|1px>|<table|<row|<cell|5
bits>|<cell|3 bits>|<cell|3 bits>|<cell|5
bits>>|<row|<cell|<math|I>>|<cell|<math|R>>|<cell|<math|R<rprime|'>>>|<cell|<math|d>>>>>>
<paragraph|Format <math|J>><tabular|<tformat|<cwith|2|2|1|2|cell-lborder|1px>|<cwith|2|2|1|2|cell-bborder|1px>|<cwith|2|2|1|2|cell-tborder|1px>|<cwith|2|2|2|2|cell-rborder|1px>|<cwith|2|2|1|-1|cell-halign|c>|<table|<row|<cell|5
bits>|<cell|11 bits>>|<row|<cell|<math|I>>|<cell|<math|d>>>>>>
<section|Tableau d'instructions>
Certain noms d'instuctions sont en <em|italique>, il s'agit de signifier
qu'il s'agit d'un alias (optionnel) pour une autre instruction.
<big-table|<tabular*|<tformat|<cwith|1|1|1|-1|cell-bborder|1px>|<table|<row|<cell|<strong|<math|I>>>|<cell|<strong|format>>|<cell|<strong|<math|f>>>|<cell|<strong|description>>|<cell|<strong|action>>|<cell|<strong|valeurs
sign�s ?>>>|<row|<cell|00000>|<cell|R>|<cell|0>|<cell|add>|<cell|<math|R\<leftarrow\>R<rsub|A>+R<rsub|B>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|1>|<cell|sub>|<cell|<math|R\<leftarrow\>R<rsub|A>-R<rsub|B>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|2>|<cell|mul>|<cell|<math|R\<leftarrow\>lo<around*|(|R<rsub|A>\<times\>R<rsub|B>|)>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|>|<cell|>|<cell|<math|E\<leftarrow\>hi<around*|(|R<rsub|A>\<times\>R<rsub|B>|)>>
si <math|E\<neq\>R>>|<cell|>>|<row|<cell|>|<cell|>|<cell|3>|<cell|div>|<cell|<math|R\<leftarrow\>q<around*|(|R<rsub|A>,R<rsub|B>|)>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|>|<cell|>|<cell|<math|E\<leftarrow\>r<around*|(|R<rsub|A>,R<rsub|B>|)>>
si <math|E\<neq\>R>>|<cell|>>|<row|<cell|00001>|<cell|R>|<cell|0>|<cell|addu>|<cell|idem
add>|<cell|non sign�>>|<row|<cell|>|<cell|>|<cell|1>|<cell|subu>|<cell|idem
sub>|<cell|non sign�>>|<row|<cell|>|<cell|>|<cell|2>|<cell|mulu>|<cell|idem
mul>|<cell|non sign�>>|<row|<cell|>|<cell|>|<cell|3>|<cell|divu>|<cell|idem
div>|<cell|non sign�>>|<row|<cell|00010>|<cell|R>|<cell|0>|<cell|or>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<vee\>R<rsub|B>|)>>>|<cell|>>|<row|<cell|>|<cell|>|<cell|1>|<cell|and>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<wedge\>R<rsub|B>|)>>>|<cell|>>|<row|<cell|>|<cell|>|<cell|2>|<cell|xor>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<oplus\>R<rsub|B>|)>>>|<cell|>>|<row|<cell|>|<cell|>|<cell|3>|<cell|nor>|<cell|<math|R\<leftarrow\>not
<around*|(|R<rsub|A>\<vee\>R<rsub|B>|)>>>|<cell|>>|<row|<cell|00011>|<cell|R>|<cell|0>|<cell|lsl>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<ll\>R<rsub|B>|)>>>|<cell|>>|<row|<cell|>|<cell|>|<cell|1>|<cell|<em|lsl>>|<cell|>|<cell|>>|<row|<cell|>|<cell|>|<cell|2>|<cell|lsr>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<gg\>R<rsub|B>|)>>
(logical)>|<cell|(non sign�)>>|<row|<cell|>|<cell|>|<cell|3>|<cell|asr>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<gg\>R<rsub|B>|)>>
(arith)>|<cell|(sign�)>>|<row|<cell|00100>|<cell|R>|<cell|0>|<cell|<em|se>>|<cell|>|<cell|>>|<row|<cell|>|<cell|>|<cell|1>|<cell|<em|sne>>|<cell|>|<cell|>>|<row|<cell|>|<cell|>|<cell|2>|<cell|se>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>=R<rsub|B>?1:0|)>>>|<cell|>>|<row|<cell|>|<cell|>|<cell|3>|<cell|sne>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<neq\>R<rsub|B>?1:0|)>>>|<cell|>>|<row|<cell|00101>|<cell|R>|<cell|0>|<cell|slt>|<cell|<math|R<rsub|>\<leftarrow\><around*|(|R<rsub|A>\<less\>R<rsub|B>?1:0|)>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|1>|<cell|sle>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<leqslant\>R<rsub|B>?1:0|)>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|2>|<cell|sltu>|<cell|<math|R<rsub|>\<leftarrow\><around*|(|R<rsub|A>\<less\>R<rsub|B>?1:0|)>>>|<cell|non
sign�>>|<row|<cell|>|<cell|>|<cell|3>|<cell|sleu>|<cell|<math|R\<leftarrow\><around*|(|R<rsub|A>\<leqslant\>R<rsub|B>?1:0|)>>>|<cell|non
sign�>>|<row|<cell|00110>|<cell|I>|<cell|>|<cell|incri>|<cell|<math|R\<leftarrow\><around*|(|R+d|)>>>|<cell|<math|d>
sign�>>|<row|<cell|00111>|<cell|I>|<cell|>|<cell|shi>|<cell|<math|R\<leftarrow\><around*|(|R\<ll\>d|)>>>|<cell|<math|d>
sign�>>|<row|<cell|01000>|<cell|J>|<cell|>|<cell|j>|<cell|<math|PC\<leftarrow\>PC+d>>|<cell|>>|<row|<cell|01001>|<cell|J>|<cell|>|<cell|jal>|<cell|<math|F\<leftarrow\><around*|(|PC+2|)>
; PC\<leftarrow\>PC+d>>|<cell|>>|<row|<cell|01010>|<cell|R<math|>>|<cell|0>|<cell|jr>|<cell|<math|PC\<leftarrow\>R>>|<cell|>>|<row|<cell|>|<cell|<math|>>|<cell|1>|<cell|jalr>|<cell|<math|><math|F\<leftarrow\><around*|(|PC+2|)>
; PC\<leftarrow\>R>>|<cell|>>|<row|<cell|>|<cell|>|<cell|2>|<cell|jer>|<cell|if
<math|R<rsub|A>=R<rsub|B>> then <math|PC\<leftarrow\>R<rsub|>>>|<cell|>>|<row|<cell|>|<cell|>|<cell|3>|<cell|jner>|<cell|if
<math|R<rsub|A>\<neq\>R<rsub|B>> then <math|PC\<leftarrow\>R<rsub|>>>|<cell|>>|<row|<cell|01011>|<cell|R>|<cell|0>|<cell|jltr>|<cell|if
<math|R<rsub|A>\<less\>R<rsub|B>> then <math|PC\<leftarrow\>R<rsub|>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|1>|<cell|jler>|<cell|if
<math|R<rsub|A>\<leqslant\>R<rsub|B>> then
<math|PC\<leftarrow\>R<rsub|>>>|<cell|sign�>>|<row|<cell|>|<cell|>|<cell|2>|<cell|jltru>|<cell|if
<math|R<rsub|A>\<less\>R<rsub|B>> then <math|PC\<leftarrow\>R<rsub|>>>|<cell|non
sign�>>|<row|<cell|>|<cell|>|<cell|3>|<cell|jleru>|<cell|if
<math|R<rsub|A>\<leqslant\>R<rsub|B>> then
<math|PC\<leftarrow\>R<rsub|>>>|<cell|non
sign�>>|<row|<cell|01100>|<cell|J>|<cell|>|<cell|lra>|<cell|<math|E\<leftarrow\>PC+d>>|<cell|<math|d>
sign�>>|<row|<cell|01101>|<cell|>|<cell|>|<cell|<em|nop>>|<cell|>|<cell|>>|<row|<cell|01110>|<cell|>|<cell|>|<cell|<em|nop>>|<cell|>|<cell|>>|<row|<cell|01111>|<cell|>|<cell|>|<cell|hlt>|<cell|halt
microprocessor (infinite loop)>|<cell|>>|<row|<cell|10000>|<cell|K>|<cell|>|<cell|lw>|<cell|<math|R\<leftarrow\>mem<around*|(|R<rprime|'>+d|)>>
(16 bits)>|<cell|>>|<row|<cell|10001>|<cell|K>|<cell|>|<cell|sw>|<cell|<math|mem<around*|(|R<rprime|'>+d|)>\<leftarrow\>R>
(16 bits)>|<cell|>>|<row|<cell|10010>|<cell|K>|<cell|>|<cell|lb>|<cell|<math|R<rsub|lo>\<leftarrow\>mem<around*|(|R<rprime|'>+d|)>
; R<rsub|hi>\<leftarrow\>0> (8 bits)>|<cell|>>|<row|<cell|10011>|<cell|K>|<cell|>|<cell|sb>|<cell|<math|mem<around*|(|R<rprime|'>+d|)>\<leftarrow\>R<rsub|lo>>
(8 bits)>|<cell|>>|<row|<cell|10100>|<cell|R>|<cell|*>|<cell|lwr>|<cell|<math|R\<leftarrow\>mem<around*|(|R<rsub|A>+R<rsub|B>|)>>
(16 bits)>|<cell|>>|<row|<cell|10101>|<cell|R>|<cell|*>|<cell|swr>|<cell|<math|mem<around*|(|R<rsub|A>+R<rsub|B>|)>\<leftarrow\>R>
(16 bits)>|<cell|>>|<row|<cell|10110>|<cell|R>|<cell|*>|<cell|lbr>|<cell|<math|R<rsub|lo>\<leftarrow\>mem<around*|(|R<rsub|A>+R<rsub|B>|)>
; R<rsub|hi>\<leftarrow\>0> (8 bits)>|<cell|>>|<row|<cell|10111>|<cell|R>|<cell|*>|<cell|sbr>|<cell|<math|mem<around*|(|R<rsub|A>+R<rsub|B>|)>\<leftarrow\>R<rsub|lo><rsup|>>
(8 bits)>|<cell|>>|<row|<cell|11000>|<cell|I>|<cell|>|<cell|lil>|<cell|<math|R<rsub|lo>\<leftarrow\>d>>|<cell|>>|<row|<cell|11001>|<cell|I>|<cell|>|<cell|lilz>|<cell|<math|R<rsub|lo>\<leftarrow\>d
; R<rsub|hi>\<leftarrow\>0>>|<cell|>>|<row|<cell|11010>|<cell|I>|<cell|>|<cell|liu>|<cell|<math|R<rsub|hi>\<leftarrow\>d>>|<cell|>>|<row|<cell|11011>|<cell|I>|<cell|>|<cell|liuz>|<cell|<math|R<rsub|hi>\<leftarrow\>d
; R<rsub|lo>\<leftarrow\>0>>|<cell|>>|<row|<cell|11100>|<cell|>|<cell|>|<cell|<em|nop>>|<cell|>|<cell|>>|<row|<cell|11101>|<cell|>|<cell|>|<cell|<em|nop>>|<cell|>|<cell|>>|<row|<cell|11110>|<cell|>|<cell|>|<cell|<em|nop>>|<cell|>|<cell|>>|<row|<cell|11111>|<cell|>|<cell|>|<cell|nop<samp|>>|<cell|<math|\<varnothing\>>>|<cell|>>>>>|Instructions
reconnues par le microproceseur>
L'assembleur propose �galement quelques instructions \S �tendues \T
permettant de faciliter la programmation :
<big-table|<tabular|<tformat|<cwith|1|1|1|-1|cell-bborder|1px>|<table|<row|<cell|<strong|Nom>>|<cell|<strong|Action>>|<cell|<strong|Code
assembleur de base �quivalent>>>|<row|<cell|push
<math|R>>|<cell|<math|G\<leftarrow\>G-2 ;mem<around*|(|G|)>\<leftarrow\>R
>>|<cell|incri <math|G,-2>>>|<row|<cell|>|<cell|>|<cell|sw
<math|R\<nocomma\>>, <math|G>>>|<row|<cell|pop
<math|R>>|<cell|<math|R\<leftarrow\>mem<around*|(|G|)> ;
G\<leftarrow\>G+2>>|<cell|lw <math|R>, <math|G>>>|<row|<cell|>|<cell|>|<cell|incri
<math|G>, 2>>|<row|<cell|move <math|R,R<rsub|A>>>|<cell|<math|R\<leftarrow\>R<rsub|A>>>|<cell|add
<math|R>, <math|R<rsub|A>>, <math|Z>>>|<row|<cell|addi, subi,
...>|<cell|<math|R\<leftarrow\>R<rsub|A>+d>>|<cell|(utilise E comme
registre temporaire)>>|<row|<cell|not <math|R,R<rsub|A>>>|<cell|<math|R\<leftarrow\>not
R<rsub|A>>>|<cell|<math|nor R,R<rsub|A>,Z>>>|<row|<cell|jz <math|R>,
addr>|<cell|if <math|R=0> then <math|PC\<leftarrow\>addr>>|<cell|lil E,
lo(addr) ; liu E, hi(addr) OU lilz E, addr>>|<row|<cell|>|<cell|>|<cell|jer
R, E, Z>>|<row|<cell|jnz <math|R>, addr>|<cell|if <math|R\<neq\>0> then
<math|PC\<leftarrow\>addr>>|<cell|lil E, lo(addr) ; liu E, hi(addr) OU lilz
E, addr>>|<row|<cell|>|<cell|>|<cell|jner R, E, Z>>>>>|Instructions
suppl�mentaires (produites par l'assembleur)>\
</body>
<\initial>
<\collection>
<associate|language|french>
</collection>
</initial>
<\references>
<\collection>
<associate|auto-1|<tuple|1|1>>
<associate|auto-10|<tuple|4|2>>
<associate|auto-11|<tuple|5|2>>
<associate|auto-12|<tuple|4|2>>
<associate|auto-13|<tuple|3|3>>
<associate|auto-14|<tuple|4|4>>
<associate|auto-15|<tuple|4|?>>
<associate|auto-16|<tuple|4|?>>
<associate|auto-17|<tuple|5|?>>
<associate|auto-2|<tuple|2|1>>
<associate|auto-3|<tuple|1|2>>
<associate|auto-4|<tuple|2|2>>
<associate|auto-5|<tuple|3|2>>
<associate|auto-6|<tuple|3.1|2>>
<associate|auto-7|<tuple|1|2>>
<associate|auto-8|<tuple|2|2>>
<associate|auto-9|<tuple|3|2>>
</collection>
</references>
<\auxiliary>
<\collection>
<\associate|table>
<tuple|normal|Memory map|<pageref|auto-3>>
<tuple|normal|Addresses MMIO|<pageref|auto-4>>
<tuple|normal|Instructions reconnues par le
microproceseur|<pageref|auto-13>>
<tuple|normal|Instructions suppl�mentaires (produites par
l'assembleur)|<pageref|auto-14>>
</associate>
<\associate|toc>
<vspace*|1fn><with|font-series|<quote|bold>|math-font-series|<quote|bold>|Registres>
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-1><vspace|0.5fn>
<vspace*|1fn><with|font-series|<quote|bold>|math-font-series|<quote|bold>|M�moire>
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-2><vspace|0.5fn>
<vspace*|1fn><with|font-series|<quote|bold>|math-font-series|<quote|bold>|Jeu
d'instruction> <datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-5><vspace|0.5fn>
<with|par-left|<quote|1.5fn>|Types d'instructions
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-6>>
<with|par-left|<quote|6fn>|Format de base
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-7><vspace|0.15fn>>
<with|par-left|<quote|6fn>|Format <with|mode|<quote|math>|R>
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-8><vspace|0.15fn>>
<with|par-left|<quote|6fn>|Format <with|mode|<quote|math>|I>
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-9><vspace|0.15fn>>
<with|par-left|<quote|6fn>|Format K
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-10><vspace|0.15fn>>
<with|par-left|<quote|6fn>|Format <with|mode|<quote|math>|J>
<datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-11><vspace|0.15fn>>
<vspace*|1fn><with|font-series|<quote|bold>|math-font-series|<quote|bold>|Tableau
d'instructions> <datoms|<macro|x|<repeat|<arg|x>|<with|font-series|medium|<with|font-size|1|<space|0.2fn>.<space|0.2fn>>>>>|<htab|5mm>>
<no-break><pageref|auto-12><vspace|0.5fn>
</associate>
</collection>
</auxiliary>
|
