RDnļƒ

Name

Read Data from Ram Status Character

Function

The 4-bits of status character n for the previously
selected RAM register are transferred to the accumulator.

Syntax

RD0, RD1, RD2, RD3

Assembled

Binary

11101100, 11101101, 11101110, 11101111,

Decimal

236, 237, 238, 239

Hexadecimal

0xEC, 0xED, 0xEE, 0xEF

Symbolic

 ../../_images/rdn-sym.png

Execution

1 word, 8-bit code and an execution time of 10.3 \({\mu}\) sec

Side-effects

Not Applicable

Implemented

rdn

Detailed Description

The DATA RAM status character whose number from 0 to 3 is specified by ā€œnā€, associated with the DATA RAM register specified by the last SRC instruction, is loaded into the accumulator.

The carry bit and the status character are not affected.

The DATA RAM status character is encoded in the opcode as shown below:

../../_images/rdn.png

Example program

The example program will read the contents of DATA RAM status character 3 of register 0 of chip 0 of the currently selected DATA RAM bank into the accumulator.

/ Example program
FIM   2P  5
SRC   2P
RD3