公开(公告)号：US20040215996A1

公开(公告)日：2004-10-28

申请号：US10811898

申请日：2004-03-30

Applicant: Renesas Technology Corp.

Inventor： Motoki Kanamori ,  Kunihiro Katayama ,  Yasuhiro Nakamura ,  Satoshi Yoshida ,  Shinsuke Asari

IPC: G06F001/04

CPC classification number: G11C7/1045 ,  G06K19/077 ,  G06K19/07732 ,  G11C16/102 ,  G11C29/02 ,  G11C29/022 ,  G11C29/028 ,  G11C29/50012

Abstract: The invention intends to provide a memory card conforming to an HS-MMC mode in a standard of a multimedia card, while securing compatibility of both standards of the multimedia card and an SD card. In a normal MMC mode, the data is outputted at a fall edge of a clock signal. A frequency of the clock signal is about 20 MHz. When the data is outputted at the fall edge of the clock signal, data output is in time for a next clock signal. When a parameter null1null is set to a timing register provided in a host interface, the memory card is transitioned into the HS-MMC mode. In the HS-MMC mode, a clock signal frequency is increased to about 52 MHz. Here, the data is outputted at the rise edge of the clock signal, whereby the data output is brought in time for the rise edge of the next clock signal.

Abstract translation: 本发明旨在提供符合多媒体卡标准中的HS-MMC模式的存储卡，同时确保多媒体卡的标准和SD卡的兼容性。 在正常的MMC模式中，数据在时钟信号的下降沿输出。 时钟信号的频率约为20MHz。 当在时钟信号的下降沿输出数据时，下一个时钟信号的数据输出是及时的。 当将参数'1'设置为主机接口中提供的定时寄存器时，存储卡被转换到HS-MMC模式。 在HS-MMC模式下，时钟信号频率增加到大约52MHz。 这里，在时钟信号的上升沿输出数据，从而数据输出及时输出到下一个时钟信号的上升沿。