| US 7,535,792 B2 | ||
| Data transmission control device, and data transmission control method | ||
| Takeshi Saito, Shiojiri (Japan) | ||
| Assigned to Seiko Epson Corporation, Tokyo (Japan) | ||
| Filed on Oct. 18, 2007, as Appl. No. 11/874,641. | ||
| Claims priority of application No. 2006-301051 (JP), filed on Nov. 07, 2006. | ||
| Prior Publication US 2008/0106961 A1, May 08, 2008 | ||
| Int. Cl. G11C 8/18 (2006.01) | ||
| U.S. Cl. 365—233.19 [365/233.1; 365/238.5] | 4 Claims |
| 1. A data transmission control device comprising:
a memory control unit that is connected to a DRAM, and accesses to the DRAM in accordance with a read/write request from various
devices that request read/write of data from/into the DRAM; and
a command control unit that issues an active command of designating a row address of the DRAM to start a memory access cycle
when the read/write request is made, and issues a precharge command to the DRAM to end the memory access cycle, and that prohibits
issuance of a precharge command in a previous memory cycle if the issuance of the precharge command is unnecessary,
wherein the command control unit
determines that the issuance of the precharge command is unnecessary if another read/write request from/into the same page
as a page requested in a memory access cycle is made, and
determines that the issuance of the precharge command is necessary if another read/write request from/into a page different
from a page requested in a memory access cycle is made, or no read/write request is repeated with a predetermined number of
times, which are equal to or greater than two, as an upper limit.
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