Program status word (psw) – Texas Instruments MSC1210 User Manual

Page 317

Advertising
background image

Bit Addressable SFRs (alphabetical)

F-7

Bit-Addressable SFRs (alphabetical)

Program Status Word (PSW)

SFR Name:

PSW

SFR Address:

D0

H

Bit−Addressable: Yes

Bit−Definitions:

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

Name

CY

AC

F0

RS1

RS0

OV

P

Bit Address

D7H

D6H

D5H

D4H

D3H

D2H

D1H

D0H

CY—Carry Flag. Set or cleared by instructions ADD, ADDC, SUBB, MUL, and
DIV.

AC—Auxiliary Carry. Set or cleared by instructions ADD, ADDC.

F0—Flag 0. General flag available to developer for user-defined purposes.

RS1/RS0—Register Select Bits. These two bits, taken together, select the
register bank used when using R registers R0 through R7, according to the fol-
lowing table:

RS1

RS0

Register Bank

Register Bank Addresses

0

0

0

00

H

−07

H

0

1

1

08

H

−0F

H

1

0

2

10

H

−17

H

1

1

3

18

H

−1F

H

OV—Overflow Flag. Set or cleared by instructions ADD, ADDC, SUBB, and
DIV.

P—Parity Flag. Set or cleared automatically by core to establish even parity
with the accumulator, so that the number of bits set in the accumulator plus the
value of the parity bit will always equal an even number.

Advertising