What is the byte address for Port 1?
5″ sets high bit 5 of port 1. Remember that DO is the LSB and D7 is the MSB. As we mentioned earlier in this chapter, every SFR register is assigned a byte address and ports PO -P3 are part of the SFR. For example, PO is assigned byte address 80H, and PI has address of 90H as shown in Figure 5-2.
Which is bit addressable register?
Which of the following is bit-addressable register? Explanation: The registers, accumulator, PSW, B, P0, P1, P2, P3, IP, IE, TCON and SCON are all bit-addressable registers. Explanation: The registers, DPH and DPL are the higher and lower bytes of a 16-bit register DPTR.
What bit addressing?
Bit-addressable objects are objects that may be addressed as words or as bits. Only data objects that occupy the bit-addressable area of the 8051 internal memory fall into this category. The Cx51 Compiler places variables declared with the bdata memory type into the bit-addressable area.
How is register addressed?
Register mode: In register addressing the operand is placed in one of 8 bit or 16 bit general purpose registers. The data is in the register that is specified by the instruction. Here one register reference is required to access the data.
What is address register used for?
Address registers are designed to make it easy to index into the array of constant registers. The address registers allow you to provide a signed integer offset into the constant registers.
What is the function of the address register?
In a computer, the memory address register (MAR) is the CPU register that either stores the memory address from which data will be fetched to the CPU, or the address to which data will be sent and stored.
How does memory address register work?
memory address register (MAR) – holds the address of the current instruction that is to be fetched from memory, or the address in memory to which data is to be transferred. memory data register (MDR) – holds the contents found at the address held in the MAR, or data which is to be transferred to main memory.
Which register is a general purpose processing register?
The general purpose registers are used to store temporary data in the time of different operations in microprocessor. 8086 has eight general purpose registers. This is the accumulator. It is 16-bit registers, but it is divided into two 8-bit registers.
Which of the following is 16-bit register?
Which of the following is a 16-bit register? Explanation: AX is a 16-bit register used as accumulator, with lower 8-bits designated as AL and higher 8-bits as AH. 4.
Which is not special function register?
Which of the following is not a special function register? Explanation: Accumulator is a general function register, which can be used for multiple functions. Explanation: 8085 contains 5 flags such as sign flag, zero flag, parity flag, auxiliary carry flag, and carry flag. 9.
What are the types of special purpose register?
Three types of special-purpose registers are the instruction register, instruction pointer, and program status word. Some Mostly used Registers are Accumulator(AC), Data Register(DR), Address Register(AR), Program Counter(PC), Memory Data Register (MDR), Index Register(IR), Memory Buffer Register(MBR).
Is instruction register a special purpose register?
A special purpose register is one that has a specific control or data handling task to carry out. There are a number of special purpose registers within the CPU….Accumulator.
| LDA 3001 | This instruction will load the data at address 3001 into the accumulator |
|---|---|
| ADC #3 | This instruction adds 3 to the content of the accumulator |