Chapter 2

Name four manufacturers of the 8051 microcontroller, besides Intel.

• Siemens

  • Advanced Micro Devices

  • Fujitsu

  • Philips

• Zilog

  MOS Technology

  AMD

  Nvidia

Which device in the MCS-51TM family would probably be used for a product that will be manufactured in large quantities with a large on-chip program?

• 8032

• 8052

• 8051

• 8031

Answer explanation

8052:

8k ---> large memory

ROM is cheaper than EPROM in large quantities

What instruction could be used to set the least-significant bit at byte address 25h?

• SETB 25h

• SETB 2Fh

• SETB 2Bh

• SETB 28h

Answer explanation

What instruction sequence could be used to place the logical OR of the bits at bit addresses 00h and 01h into bit address 02h?

• MOV C, 00h

  ORL C, 00h

  MOV 02h, C

• MOV A, 00h

  ORL C, 00h

  MOV 02h, C

• MOV C, 00h

  OR C, 00h

  MOV 02h, C

What instruction sequence could be used to read bit 0 of Port 0 and write the state of the bit read to bit 0 of Port 3?

• MOV A, P0.0

  MOV P3.0, A

• MOV C, P0.0

  MOV P3.0, C

• MOV P3.0, P0.0

• MOV C, P3.0

  MOV P0.0, C

Illustrate an instruction sequence to read bit 0 and bit 1 of Port 0 and write a status condition to bit 0 of Port 3 as follows: If both bits read are 1, write a 1 to the output status bit, otherwise write a 0.

• MOV C, P0.0

  XRL C, P0.1

  MOV P3.0, C

• MOV C, P0.0

  ORL C, P0.1

  MOV P3.0, C

• MOV C, P0.0

  ANL C, P0.1

  MOV P3.0, C

• MOV C, P0.0

  ANL C, P0.1

  MOVC P3.0

What bit addresses are set to 1 as a result of the following instruction

MOV 26h, #26h

• 30, 31, 31

• 31, 32, 35

• 34, 35, 36

• 32, 33, 37

What 2-byte instruction has the same effect as the following 3-byte instruction?

MOV 0E0h, #55h

What is the value of the 8051’s stack pointer immediately after a system reset?

What instruction would be used to initialize the stack pointer to create a 32-byte stack at the top of memory on the 8052