Consider the following statements regarding Stack in 8051:
1. Stack operates on LIFO principle.
2. PUSH increases stack pointer.
3. POP decreases stack pointer.
Which of the above statements is/are correct?
Answer & step-by-step solution
The classic 8051 is an 8-bit Harvard-style microcontroller with separate code and data spaces. On reset the stack pointer is 07H, so the first PUSH stores at 08H. Key relation: Reset SP=07H; classic internal RAM=128 bytes; standard ROM=4 KB.
Exam focus: Remember 07H for stack pointer reset. Common trap: 00H is not the reset value of the 8051 stack pointer.
Statement-wise Verification
- Statement 1 - Correct.
Stack operates on LIFO principle.
Remember 07H for stack pointer reset. - Statement 2 - Correct.
PUSH increases stack pointer.
On reset the stack pointer is 07H, so the first PUSH stores at 08H. - Statement 3 - Correct.
POP decreases stack pointer.
Remember 07H for stack pointer reset.
Core Concept
The classic 8051 is an 8-bit Harvard-style microcontroller with separate code and data spaces. The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority. On reset the stack pointer is 07H, so the first PUSH stores at 08H.
Formula / Key Relationship
Reset SP=07H; classic internal RAM=128 bytes; standard ROM=4 KB.
Why the Other Options Are Wrong
Option A is incorrect because it omits correct statement(s) 3. Option B is incorrect because it omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2.
Exam Shortcut / Approach
Remember 07H for stack pointer reset.
Common Mistake
00H is not the reset value of the 8051 stack pointer.
Quick Revision
PUSH POP and Stack Pointer is linked with Stack, 8051 Microcontroller and Microprocessors and Microcontrollers. Remember 07H for stack pointer reset.
8051 में स्टैक के संबंध में निम्नलिखित कथनों पर विचार कीजिए:
1. स्टैक LIFO सिद्धांत पर कार्य करता है।
2. PUSH स्टैक पॉइंटर बढ़ाता है।
3. POP स्टैक पॉइंटर घटाता है।
उपरोक्त में से कौन-सा/से कथन सही है/हैं?
उत्तर और चरणबद्ध हल
D — 1, 2 और 3। 8051 स्टैक LIFO है और ऊपर की ओर बढ़ता है: PUSH पहले SP बढ़ाता है फिर डेटा लिखता है, POP डेटा पढ़कर SP घटाता है। रीसेट पर SP = 07H, इसलिए पहला PUSH 08H पर जाता है।
विस्तृत हल (मूल भाषा में)
Statement-wise Verification
- Statement 1 - Correct.
Stack operates on LIFO principle.
Remember 07H for stack pointer reset. - Statement 2 - Correct.
PUSH increases stack pointer.
On reset the stack pointer is 07H, so the first PUSH stores at 08H. - Statement 3 - Correct.
POP decreases stack pointer.
Remember 07H for stack pointer reset.
Core Concept
The classic 8051 is an 8-bit Harvard-style microcontroller with separate code and data spaces. The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority. On reset the stack pointer is 07H, so the first PUSH stores at 08H.
Formula / Key Relationship
Reset SP=07H; classic internal RAM=128 bytes; standard ROM=4 KB.
Why the Other Options Are Wrong
Option A is incorrect because it omits correct statement(s) 3. Option B is incorrect because it omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2.
Exam Shortcut / Approach
Remember 07H for stack pointer reset.
Common Mistake
00H is not the reset value of the 8051 stack pointer.
Quick Revision
PUSH POP and Stack Pointer is linked with Stack, 8051 Microcontroller and Microprocessors and Microcontrollers. Remember 07H for stack pointer reset.
8051માં સ્ટેક અંગે નીચેનાં વિધાનો ધ્યાનમાં લો:
1. સ્ટેક LIFO સિદ્ધાંત પર કાર્ય કરે છે.
2. PUSH સ્ટેક પોઇન્ટર વધારે છે.
3. POP સ્ટેક પોઇન્ટર ઘટાડે છે.
ઉપરોક્તમાંથી કયું/કયાં વિધાન સાચું/સાચાં છે?
જવાબ અને પગલાવાર ઉકેલ
D — 1, 2 અને 3. 8051 સ્ટેક LIFO છે અને ઉપર તરફ વધે છે: PUSH પહેલાં SP વધારે છે પછી ડેટા લખે છે, POP ડેટા વાંચીને SP ઘટાડે છે. રીસેટ પર SP = 07H, તેથી પહેલો PUSH 08H પર જાય છે.
વિગતવાર ઉકેલ (મૂળ ભાષામાં)
Statement-wise Verification
- Statement 1 - Correct.
Stack operates on LIFO principle.
Remember 07H for stack pointer reset. - Statement 2 - Correct.
PUSH increases stack pointer.
On reset the stack pointer is 07H, so the first PUSH stores at 08H. - Statement 3 - Correct.
POP decreases stack pointer.
Remember 07H for stack pointer reset.
Core Concept
The classic 8051 is an 8-bit Harvard-style microcontroller with separate code and data spaces. The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority. On reset the stack pointer is 07H, so the first PUSH stores at 08H.
Formula / Key Relationship
Reset SP=07H; classic internal RAM=128 bytes; standard ROM=4 KB.
Why the Other Options Are Wrong
Option A is incorrect because it omits correct statement(s) 3. Option B is incorrect because it omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2.
Exam Shortcut / Approach
Remember 07H for stack pointer reset.
Common Mistake
00H is not the reset value of the 8051 stack pointer.
Quick Revision
PUSH POP and Stack Pointer is linked with Stack, 8051 Microcontroller and Microprocessors and Microcontrollers. Remember 07H for stack pointer reset.
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