System including address generator and address generator
First Claim
1. A system including an address generator for generating an address needed at time of memory access, said address generator comprising:
- an address updater for updating an address by adding an increment of the address; and
an address increment selector having a plurality of counters in which respective initial values can be set independently and a plurality of registers, each for specifying increment of said address, said address increment selector selecting the increment of the address on the basis of a value in at least one counter included in the counters.
1 Assignment
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Accused Products
Abstract
There are provided a system including an address generator and its address generator, capable of generating an address needed for resolution conversion or the like of display data, by using an adder and counters without using a multiplier, which is disadvantageous as regards the mounting area and operation speed when mounting the address generator on an integrated circuit. A first portion for selecting a value from a plurality of values prepared to calculate the next address and adding the selected value, and a second portion for generating a signal to control selection of the value to be added are prepared. A plurality of counters are prepared in the second portion, and the value to be added is selected based on values in these counters. This address generator is incorporated in a DMA controller, memory access controller, display controller or the like, to implement resolution conversion or the like.
4 Citations
20 Claims
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1. A system including an address generator for generating an address needed at time of memory access, said address generator comprising:
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an address updater for updating an address by adding an increment of the address; and
an address increment selector having a plurality of counters in which respective initial values can be set independently and a plurality of registers, each for specifying increment of said address, said address increment selector selecting the increment of the address on the basis of a value in at least one counter included in the counters. - View Dependent Claims (2, 3, 4, 5, 15, 16, 17, 18, 19)
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6. A system including an address generator for generating an address needed at time of memory access, said address generator comprising:
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a start address register for specifying a start address;
a first counter;
a first initial value register for specifying a count period of said first counter;
a second counter for counting every count period of said first counter;
a second initial value register for specifying an initial value of said second counter;
a first step register for specifying an increment of the address when said first counter has a value different from a specific value; and
a second step register and a third step register selected on the basis of a value in said second counter to specify the increment of the address when said first counter has a specific value and said second counter has a value different from a specific value. - View Dependent Claims (7, 8)
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9. A system including an address generator for generating an address needed at time of memory access, said address generator comprising:
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a start address register for specifying a start address;
a first counter;
a first initial value register for specifying a count period of said first counter;
a second counter for counting every count period of said first counter;
a second initial value register for specifying an initial value of said second counter;
a third counter for counting every count period of said first counter;
a third initial value register for specifying an initial value of said third counter;
a first step register for specifying an increment of the address to be used when said first counter has a value different from a specific value;
a second step register for specifying the increment of the address to be used when said first counter has a specific value and said third counter has a specific value; and
a third step register for specifying the increment of the address to be used when said first counter has a specific value and said third counter has a value different from a specific value. - View Dependent Claims (10, 11)
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12. A system including an address generator for generating an address needed at time of memory access, said address generator comprising:
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a start address register for specifying a start address;
a first counter;
a first initial value register for specifying a count period of said first counter;
a second counter for counting every count period of said first counter;
a second initial value register for specifying an initial value of said second counter;
a third counter for counting every count period of said second counter;
a third initial value register for specifying an initial value of said third counter;
a first step register for specifying an increment of the address to be used when said first counter has a value different from a specific value;
a second step register for specifying the increment of the address to be used when said first counter has a specific value and said second counter has a specific value; and
a third step register for specifying the increment of the address to be used when said first counter has a specific value and said second counter has a value different from a specific value. - View Dependent Claims (13, 14)
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20. An address generator for generating an address needed at time of memory access, said address generator comprising:
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an address updater for updating an address by adding an increment of the address; and
an address increment selector having a plurality of counters in which respective initial values can be set independently, said address increment selector selecting the increment of the address on the basis of values in the counters.
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Specification