JPS58103043A - Stack forming method - Google Patents

Abstract

PURPOSE:To make the stack operation high-speed, by providing an internal stack, an internal stack pointer and an external stack pointer in an operation processing device and reducing the frequency of write to and read from a storage device, to reduce a waste of time for data transfer. CONSTITUTION:An external stack pointer 7, an internal stack pointer 8, an internal stack 9, and an internal bus 10 for connecting them are provided in an operation processing device 6. In case that a stack use request is generated during the execution of a progam, data is transferred to the stack 9 under the control of the internal stack pointer 8 if data is within the range of the capacity of the internal stack 9. If data is not within the range of the capacity of the internal stack 9, data is transferred to an external stack 12 in a form of block transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an information processing device such as a microcomputer display, in which data is received and passed, and a stack is formed which is used for storing arguments when branching to a subprogram or a return address to a main program. It is about the method.

A conventional example is shown in Figure 1. A stack pointer (2) is provided in the arithmetic processing unit (1), and a storage device (3) corresponding to the address indicated by the contents of the stack pointer (2) is provided.
), and each time the memory is read or written, the contents of the stack pointer (2) are changed to the address area occupied by one word. A stack (4) is formed as an output memory. Since the stack (4) allows data to be transferred in and out without being particularly aware of the memory address in the storage device (3), it is possible to store the return address to the main program when branching to a subprogram, and to transfer data from the subprogram to the main program. Retrieving the return address when returning,
It is frequently used for saving and restoring the contents of various registers in the arithmetic processing unit (1), and for passing data between programs. An arithmetic processing unit (1) connects a bus line (5) to a storage device (3) under the control of a stack pointer (2).
) to read and write data via the bus (5
) data delay due to distributed capacity, arithmetic processing unit (1)
Data delays occur in the transmission/reception section between the storage device (3) and the bus (5) used to connect the storage device (3) and the bus (5), as well as within the transmission/reception control section. needed time.

The present invention provides a novel method for forming a stack that improves the conventional drawbacks.
internal) stack, which connects the main (
The purpose is to reduce the frequency of reading and writing to a storage device used as an external stack, reduce wasted time in data transfer, and increase speed.

An embodiment of the present invention will be described below based on the drawings. Second
In the figure, the arithmetic processing bag H(0) includes an external stack pointer (7), an internal stack pointer (8), an internal stack (9), and an internal bus bar (+()) that connects them.
It is connected to the storage device (1+) containing the external stack (1'4) via the bus (1→). The external stack pointer (7) indicates the empty head position of the external stack @, and the internal stack pointer (8 ) indicates the empty top position of the internal stack (9), and when the arithmetic processing unit (6) performs a write/read operation to the stack, data is transferred to the internal stack (1) through the internal stack pointer (8). When the processing unit (6) writes to the stack when the internal stack is full, it updates the internal stack pointer (8) without reading. After transferring the first part to the external stack @ through the stack pointer (7), it writes to the internal stack (9) and updates the internal stack pointer (8) and external stack pointer (7). When reading from the stack when it is empty, transfer part of the contents of external stack 0 to the internal stack (9) through the external stack, if pointer 7) and internal stack pointer (8), and then read from the internal stack (9). , internal stack pointer (
8) and the external stack pointer (7).

Let us now consider the case where the capacity of the internal stack (9) is 2n words and explain in more detail. When a stack use request occurs during program execution, data is received and delivered to and from the internal stack (9) under the control of the internal stack pointer (8). The internal stack (9) is configured to form a register array, and data is received and passed through the internal bus (In), so data cannot be received between registers within the arithmetic processing unit (6). can be performed as fast as passing.If a read request occurs when the data stored in the internal stack (9) is 0 words, n words are transferred from the position indicated by the external stack pointer (7). Storage device 01)
The data is stored in the internal stack (9) from the external stack 0'4 via the bus 03, and then read from the internal stack (9).

Similarly, when a write request occurs when the data stored in the internal stack (9) is 2n words, the internal stack (9) is placed at the position indicated by the stack pointer (7).
n m is stored from the busbar (13) to the outer stack o sand, and then written to the inner stack (9). In this way, the inner stack (9) and the outer stack 0
By changing the table of words transferred at one time between 4 and 4 to n instead of 2n, the number of words stored in the internal stack (9) is O or the operation frequency near 2n is reduced, and the number of words stored in the internal stack (9) and external stack 0 is reduced. This reduces the number of data transfers between internal stacks (9
) to make it easy to receive and pass data.

Generally speaking, the internal stack (9) is (i + j ten k)
(where i is a positive integer and J is an integer), when writing to the star when the internal stack (9) is full, the i word from the contents of the internal stack is written to the external stack (9). 6), and when reading from the stack when the internal stack is empty, the word is transferred from the function stack to the internal stack. ^In the oral example, i = to = n, j
I considered the case where =o, but l.

The combination of values for J and is not limited to this.

As explained above, the stack forming method of the present invention does not form the stack only on the storage device, but also provides a stack register array in the arithmetic processing unit d as an internal stack, and forms the stack on the register array. Therefore, if the number of words that does not exceed the capacity of the internal stack is handled, there is no data transfer with the external stack, and even if the capacity of the internal stack is exceeded, no data transfer with the external stack occurs. Since it takes the form of block transfer, it has the advantage that stack operations can be performed at high speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional stack forming method, and FIG. 2 is a block diagram showing a stack forming method according to the present invention. (6)...Arithmetic processing unit, (7)...External stack pointer, (8)...Internal stack pointer, (9)
Internal stack, 0()・Internal bus, 0υ...Storage device, Oj・External stack, (I)・Bus line agent Yoshihiro Morimoto

Claims (1)

[Claims] 1. Using an information processing device consisting of an arithmetic processing device, a storage device for storing programs to be executed by the arithmetic processing device and data to be handled, and a bus connecting these devices, data is exchanged within the program. In forming a first-in, last-out stack, an external stack is stored in the storage device, an internal stack is stored in the arithmetic processing unit, an internal stack pointer indicating the empty top position of the internal stack, and an empty top position of the external stack. When the arithmetic processing unit performs a write/read operation to the stack, it writes and reads data to and from the internal stack, updates the internal stack pointer, and maintains the internal stack in a full state. When writing to the stack, the contents of the internal stack are transferred to the external stack I7 and then written to the internal stack, and the internal stack pointer and the external stack pointer are updated, and when reading from the stack when the internal stack is empty. One stack forming method is characterized in that the contents of the external stack are transferred to the internal stack and then read from the internal stack and the internal stack pointer and the external stack pointer are updated. It consists of 10j 10k) words (where i is a positive integer and j is an integer), and when writing to the stack when the internal stack is full, one word from the contents of the internal stack is transferred to the external stack, 2. The stack forming method according to claim 1, wherein when reading from the stack when the internal stack is empty, words are transferred to the internal stack from one stack to the next.