AS3661 datasheet(76/87 Pages) AMSCO

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AS3661

Datasheet - D e t a i l e d D e s c r i p t i o n

8.14 Branch Instructions

8.14.1 RST

RST instruction resets Program Counter register (address 37H, 38H, or 39H) and continues executing the program

from the program start address defined in 4C-4E. Instruction takes sixteen 32 kHz clock cycles.

COMPILER COMMAND SYNTAX: RST;

This command doesn’t support any parameters.

Note: The default value for all program memory registers is 0000H, which is the RST instruction.

8.14.2 BRANCH (Numerical)

Branch instruction is mainly indented for repeating a portion of the program code several times. Branch instruction

loads step number value to program counter. Loop count parameter defines how many times the instructions inside the

loop are repeated. AS3661 supports nested looping i.e. loop inside loop. The number of nested loops is not limited.

Instruction takes sixteen 32 kHz clock cycles.

COMPILER COMMAND SYNTAX: BRN, loop count[6], step number[7];

8.14.2.1 BRN Application Example

In this application example we would like to create an infinite loop, which means the loop will never stop. The code we

want to repeat has a start address of 10d. At the end of the code we want to repeat we put the BRN command with the

program counter address 10d. Once the program execution engine executes the BRN command the program counter

jumps back to address 10d and starts executing the code from this address until it reaches again the BRN command.

COMPILER COMMAND SYNTAX: EXAMPLE: BRN, 0, 10;

Figure 35. BRN Example for execution engine 1

Table 86. BRN Parameter Description

Name

Accepted Value

Description

loop count

0-63

The number of loops to be done. 0 means an infinite loop

step number

0-95

The step number to be loaded to program counter

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