3 INSTRUCTION SET

PUSH YL

Push YL onto stack

 

 

 

 

 

 

Source Format:

PUSH YL

 

 

 

 

 

 

Operation:

SP'

SP - 1, M(SP')

YL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OP-Code:

 

1

1

1

1

1

1

0

0

1

0

0

1

FC9H

 

MSB

 

 

 

 

 

 

 

 

 

LSB

 

Type:

VI

 

 

 

 

 

 

 

 

 

 

 

Clock Cycles:

5

 

 

 

 

 

 

 

 

 

 

 

 

Flag:

 

C – Not affected

 

 

 

 

 

 

 

 

Z – Not affected

 

 

 

 

 

 

 

 

D – Not affected

 

 

 

 

 

 

 

 

I – Not affected

 

 

 

 

 

 

Description: Decrements the stack pointer by 1 and loads the contents of YL, the four low-order bits of YHL, into the data memory location addressed by SP.

Example:

 

PUSH YL

M(SP) =

23

22

21

20

 

 

 

 

 

 

 

 

 

 

 

 

20

 

 

SP

D0

CF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

21

= YL

 

Memory (CFH)

0001

0111

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

22

 

YL register

0111

0111

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23

 

 

 

 

 

 

 

 

 

 

PUSH YP

Push YP onto stack

 

 

 

 

 

 

Source Format:

PUSH YP

 

 

 

 

 

 

Operation:

SP'

SP - 1, M(SP')

YP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OP-Code:

1

1

1

1

1

1

0

0

0

1

1

1

FC7H

 

MSB

 

 

 

 

 

 

 

 

 

LSB

Type: VI

Clock Cycles: 5

Flag: C – Not affected

Z– Not affected D – Not affected I – Not affected

Description: Decrements the stack pointer by 1 and loads the contents of YP, the page part of IY, into the data memory location addressed by SP.

Example:

 

PUSH YP

M(SP) =

23

22

21

20

 

 

 

 

SP

C0

BF

 

 

 

 

 

 

20

 

 

Memory (BFH)

1111

0000

 

 

 

 

 

 

 

 

 

 

 

21

= YP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

22

 

YP register

0000

0000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23

 

 

 

 

 

 

 

 

 

 

 

 

 

S1C6200/6200A CORE CPU MANUAL

EPSON

71