Panther: Новая: http://pudsoft.com/model2/libs/libz80/z80.c /* The DAA opcode * According to the value in A and the flags set, add a value to A * * Flags set Byte (0..9)(0..9) *...

2008-02-19T12:48:37Z

Новая: http://pudsoft.com/model2/libs/libz80/z80.c <source lang="c"> /* The DAA opcode * According to the value in A and the flags set, add a value to A * * Flags set Byte (0..9)(0..9) *...

Новая страница

http://pudsoft.com/model2/libs/libz80/z80.c
<source lang="c">
/* The DAA opcode
* According to the value in A and the flags set, add a value to A
*
* Flags set Byte (0..9)(0..9)
* --------------------------------------------
* (None) + &00
* Carry:+ &60
* Subtract:+ &00
* Subtract+Carry:+ &A0
* Half-carry:+ &06
* Half-carry+Carry:+ &66
* Half-carry+Subtract:+ &FA
* Half-carry+Subtract+Carry:+ &9A
*
* Flags set Byte (0..9)(A..F)
* --------------------------------------------
* (None) + &06
* Carry:+ &66
* Subtract:+ &00
* Subtract+Carry:+ &a0
* Half-carry:+ &06
* Half-carry+Carry:+ &66
* Half-carry+Subtract:+ &fa
* Half-carry+Subtract+Carry:+ &9A
*
* Flags set Byte (A..F)(0..9)
* --------------------------------------------
* (None) + &60
* Carry:+ &60
* Subtract:+ &00
* Subtract+Carry:+ &A0
* Half-carry:+ &66
* Half-carry+Carry:+ &66
* Half-carry+Subtract:+ &fa
* Half-carry+Subtract+Carry:+ &9A
*
* Flags set Byte (A..F)(A..F)
* --------------------------------------------
* (None) + &66
* Carry:+ &66
* Subtract:+ &00
* Subtract+Carry:+ &a0
* Half-carry:+ &66
* Half-carry+Carry:+ &66
* Half-carry+Subtract:+ &fa
* Half-carry+Subtract+Carry:+ &9A
*/

static int DAA_BYTETYPE[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1 };

static byte DAA_ADJUSTMENT[4][8] = {
{ 0x00, 0x60, 0x00, 0xA0, 0x06, 0x66, 0xFA, 0x9A },
{ 0x06, 0x66, 0x00, 0xA0, 0x06, 0x66, 0xFA, 0x9A },
{ 0x60, 0x60, 0x00, 0xA0, 0x66, 0x66, 0xFA, 0x9A },
{ 0x66, 0x66, 0x00, 0xA0, 0x66, 0x66, 0xFA, 0x9A } };

static void doDAA (Z80Context *ctx)
{
/* (0..9)(0..9) = 0 */
/* (0..9)(A..F) = 1 */
/* (A..F)(0..9) = 2 */
/* (A..F)(A..F) = 3 */
int byteType = DAA_BYTETYPE[BR.A] | ((DAA_BYTETYPE[BR.A >> 4]) << 1);

int flagMask = 0;
if (GETFLAG(F_C))
flagMask |= 1;
if (GETFLAG(F_S))
flagMask |= 2;
if (GETFLAG(F_H))
flagMask |= 4;

BR.A += DAA_ADJUSTMENT[byteType][flagMask];

adjustFlags(ctx, BR.A);
}
</source>

Обсуждение:Zilog Z80/Система команд/DAA - История изменений

Panther: Новая: http://pudsoft.com/model2/libs/libz80/z80.c /* The DAA opcode * According to the value in A and the flags set, add a value to A * * Flags set Byte (0..9)(0..9) *...