HT46R065D Просмотр технического описания (PDF) - Holtek Semiconductor

Номер в каталоге

Компоненты Описание

производитель

HT46R065D

Enhanced A/D Type MCU with High Current LED Driver

Holtek Semiconductor 

HT46R064D/065D/066D

Enhanced A/D Type 8-Bit OTP MCU with LED Driver

Stack

This is a special part of the memory which is used to save the contents of the Program Counter only.

The stack is neither part of the Data or Program Memory space, and is neither readable nor writeable.

The activated level is indexed by the Stack Pointer, SP, and is neither readable nor writeable. At a

subroutine call or interrupt acknowledge signal, the contents of the Program Counter are pushed onto

the stack. At the end of a subroutine or an interrupt routine, signaled by a return instruction, RET or

RETI, the Program Counter is restored to its previous value from the stack. After a device reset, the

Stack Pointer will point to the top of the stack.

P ro g ra m C o u n te r

T o p o f S ta c k

S ta c k

P o in te r

S ta c k L e v e l 1

S ta c k L e v e l 2

S ta c k L e v e l 3

B o tto m o f S ta c k

S ta c k L e v e l 6

Device

HT46R064D

HT46R065D/HT46R066D

P ro g ra m

M e m o ry

Stack Levels

4

6

If the stack is full and an enabled interrupt takes place, the interrupt request flag will be recorded but

the acknowledge signal will be inhibited. When the Stack Pointer is decremented, by RET or RETI,

the interrupt will be serviced. This feature prevents stack overflow allowing the programmer to use

the structure more easily. However, when the stack is full, a CALL subroutine instruction can still be

executed which will result in a stack overflow. Precautions should be taken to avoid such cases

which might cause unpredictable program branching.

Arithmetic and Logic Unit - ALU

The arithmetic-logic unit or ALU is a critical area of the microcontroller that carries out arithmetic and

logic operations of the instruction set. Connected to the main microcontroller data bus, the ALU

receives related instruction codes and performs the required arithmetic or logical operations after

which the result will be placed in the specified register. As these ALU calculation or operations may

result in carry, borrow or other status changes, the status register will be correspondingly updated to

reflect these changes. The ALU supports the following functions:

· Arithmetic operations: ADD, ADDM, ADC, ADCM, SUB, SUBM, SBC, SBCM, DAA

· Logic operations: AND, OR, XOR, ANDM, ORM, XORM, CPL, CPLA

· Rotation RRA, RR, RRCA, RRC, RLA, RL, RLCA, RLC

· Increment and Decrement INCA, INC, DECA, DEC

· Branch decision, JMP, SZ, SZA, SNZ, SIZ, SDZ, SIZA, SDZA, CALL, RET, RETI

Rev. 1.00

15

January 12, 2011

Share Link: