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Connect register 7 to the B side of the ALU; Set the ALU to perform two's-complement addition; Set the ALU's carry input to zero; Store the result value in register 8; Update the condition codes from the ALU status flags (negative, zero, overflow, and carry) Microjump to a given μPC address for the next microinstruction
In computing, an arithmetic logic unit (ALU) is a combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. [ 1 ] [ 2 ] This is in contrast to a floating-point unit (FPU), which operates on floating point numbers.
In computer processors, the carry flag (usually indicated as the C flag) is a single bit in a system status register/flag register used to indicate when an arithmetic carry or borrow has been generated out of the most significant arithmetic logic unit (ALU) bit position.
It provides many of the functions found in simple, commercially available CPUs. The most complex element of the CPU is the arithmetic logic unit (ALU) which provides the computational functionality of the computer. The ALU is a combinational logic device having two 16-bit input operands and a single 16-bit output.
A common example is the Data General Nova, which was a 16-bit design that performed 16-bit math as a series of four 4-bit operations. 4-bits was the word size of a widely available single-chip ALU and thus allowed for inexpensive implementation. Using the definition being applied to the 68000, the Nova would be a 4-bit computer, or 4/16.
Support for such operations was an upgrade option rather than being a standard feature. Since the VAX's registers were 32 bits wide, a 128-bit operation used four consecutive registers or four longwords in memory. The ICL 2900 Series provided a 128-bit accumulator, and its instruction set included 128-bit floating-point and packed decimal ...
Registers are normally measured by the number of bits they can hold, for example, an 8-bit register, 32-bit register, 64-bit register, 128-bit register, or more.In some instruction sets, the registers can operate in various modes, breaking down their storage memory into smaller parts (32-bit into four 8-bit ones, for instance) to which multiple data (vector, or one-dimensional array of data ...
The term arithmetic underflow (also floating-point underflow, or just underflow) is a condition in a computer program where the result of a calculation is a number of more precise absolute value than the computer can actually represent in memory on its central processing unit (CPU).