Revision 1.1

Jun. 7, 1999

-13-

GL640USB, GL640USB-A

0: No carry-out from the 4

CA: Carry/Borrow bit

1: A carry-out from the most significant bit

0: No carry-out from the most significant bit

Value on POR: “- - 0 - - 0 0 0”

INDAR: (Address 04h/84h, Indirect address register)

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

INDAR7

INDAR6

INDAR5

INDAR4

INDAR3

INDAR2

INDAR1

INDAR0

Any instruction using the INDF register actually accesses the register pointed by the INDAR

register.

Value on POR: “x x x x x x x x”

[1]

Note 1: “x” means unknown

PORT1 (Address 06h, Port 1 data register)

R/W

R/W

R/W

R/W

R/W

PORT1.

4

PORT1.

3

PORT1.

2

PORT1.

1

PORT1.

0

PORT1 is a 5-bit latch for Port 1. Reading the PORT1 register reads the status of the pins whereas

writing to it will write to the port latch. All write operations are read-modify-write operations.

Value on POR: “- - - x x x x x”

PORT2 (Address 07h, Port 2 data register)

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

PORT2.

7

PORT2.

6

PORT2.

5

PORT2.

4

PORT2.

3

PORT2.

2

PORT2.

1

PORT2.

0

PORT2 is an 8-bit latch for Port 2. Reading the PORT2 register reads the status of the pins

whereas writing to it will write to the port latch. All write operations are read-modify-write

operations.

Value on POR: “x x x x x x x x”

PCHBUF (Address 0Ah/8Ah, Write buffer of Program Counter’s bit 10-8)

R/W

R/W

R/W