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Post by DarioG on Jul 15, 2024 9:29:13 GMT
GD24032
a 32bit CPU:
32 registers, 32bit wide
highly orthogonal instruction set
15 addressing modes: Immediate, Register Direct, Register Indirect (with and without base offset, both short and long), Register Indirect with Pre and Post increment, Pre and Post decrement, Register Indirect with opional base offset and 2 registers), Far (64bit) Register Direct and Indirect (with and without base offset)
32bit address space, optionally 64
8/16/32/64bit operations
4 CPU modes, User/IRQ/Super
32 interrupt levels
Trap handling (30 system and 64 user)
Remappable register set (for fast context switching)
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Post by DarioG on Jul 15, 2024 9:29:35 GMT
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Post by DarioG on Jul 22, 2024 19:31:49 GMT
new version: some new instructions, added conditional execution for many of them, overall optimization youtu.be/ZPQCNcxgpzM |
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Post by DarioG on Aug 4, 2024 15:16:51 GMT
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Post by DarioG on Aug 4, 2024 15:17:57 GMT
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Post by DarioG on Aug 6, 2024 11:13:01 GMT
v5, some more video BIOS + Assembler complete and bug fix  HEX print, plus CR/LF  |
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Post by DarioG on Aug 9, 2024 12:17:43 GMT
more HEX print, more features (Exception structure)  |
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Post by DarioG on Aug 10, 2024 14:40:24 GMT
some code examples
public calc_vidpos
calc_vidpos:
MOV.d R2,0x0b8000 ;(CGA base)
CLR.d R8
MOV.b R8,[cursor_y]
MUL.d R8,40*2 ; *2, char + colore
ADD.b R8,[cursor_x]
ADD.b R8,[cursor_x] ; *2, char + colore
ADD.d R2,R8
RET
hex2asc: ; entra R0=digit
AND.b R0,0xf
ADD.b R0,'0'
CMP.b R0,'9'
RET c
ADD.b R0,'A'-('9'+1)
RET
print_dec_number: ; entra R0=numero (<100000)
ENTER R10,16
CLR.B [R10--] ; marker...
TB.d R0,31
NEG nz,R0
PUSH.d R0
MOV.b R0,'-'
CALL nz,putchar
POP.d R0
print_dec_number3:
DIV.d R0,10
PUSH.d R0
MOV.d.f R0,R0 ; se resto e quoziente=0
BEQ print_dec_number2
SWAP.d R0 ; recupero il resto
ADD.b R0,'0'
MOV.B [R10--],R0
POP.d R0
AND.d R0,0xffff
JR print_dec_number3
print_dec_number2:
MOV.B.f R0,[++R10]
BEQ print_dec_number4
CALL putchar
JR print_dec_number2
print_dec_number4:
LEAVE R10
RET
org 0x800
;0800 trap gestione video: entra R8=servizio
VIDEO_SVC EQU 4
VIDEO_INIT EQU 0 ; 0=reset/init schermo R0=modo
VIDEO_CLS EQU 1 ; 1=CLS R0=colore
VIDEO_CHAR EQU 2 ; 2=PutChar R0=char R1=colore
VIDEO_SETXY EQU 3 ; 3=SetXY R0=x R1=y
VIDEO_PRINT EQU 4 ; 4=Print 0-term R0=string address R1=colore
VIDEO_SVC_MAX EQU 5
CMP.b.f R8,VIDEO_SVC_MAX
BNC trap4_err
AND.d r8,255
JMP (r8+trap4_table)
trap4_err:
CLR.b R0
RETI
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Post by DarioG on Aug 10, 2024 17:52:41 GMT
 some more debugging and fine-tuning, plus test code (itoa, etc) |
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Post by DarioG on Aug 11, 2024 22:16:21 GMT
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Post by DarioG on Aug 13, 2024 10:17:42 GMT
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