w86l488y-ay Winbond Electronics Corp America, w86l488y-ay Datasheet - Page 26

• Manufacturer Part Number: w86l488y-ay
• Description: Winbond Host Interface Sd/sdio/mmc Memory Card Bridge
• Manufacturer: Winbond Electronics Corp America

7.2
There are two different approaches for Host to detect SD/SDIO card is inserted or ejected through
W86L488Y/AY. For MMC card is just suitable for second one. First approach is detected by CD/DAT3
pin, and second is a dedicated mechanical switch on the SD/MMC slot can be connected to the GIO0
pin and set GIO0 to input direction. These two methods can be performed even if the W86L488 is in
power down state. Second approach is recommended to implement.
Approach 1, CD/DAT3 as card detection:
The CD/DAT3 of SD bus can be used as card detection after power up. This method will not be
effective when 4-bit mode activated on the SD bus is transferring. MMC card may not be utilized this
method. Some MMC cards will be configured as SPI mode after GO_IDLE_STATE (CMD0) command
is issued due to external or dedicated pulled-down resister.
Approach 2, GIO0, GIP6 as card detection (Recommended):
Some SD/MMC slots support external switch for card existing detection, the switch will be stuck on
specified state when SD/SDIO or MMC card is exist. GIO0 and GIP6 with a pull-up resister can be
used as card detection of port A and port B. SD/SDIO or MMC card inserting or removing changes the
switch state of GIO0 pin and then generates interrupt to the Host. Host may check the card state by
General I/O Port Data Reg.. The card inserted status of port A and port B also regards to Global
Status and Control Reg..
Figure 7-9 shows the waveform of GIO0 and GIOx when card is inserted and removed if GIO0 as
card insert and GIOx as write protect detection.
(no WP)
GIO0
GIOx
GIOx
Card Inserting and Removing
(WP)
Fig. 7-9 Card Insert use GIO0 and Write Protect use GIOx.
Inserting
Card is exist
(Check General I/O Port Reg.)
(Check General I/O Port Reg.)
(Check General I/O Port Reg.)
- 23 -
Publication Release Date: June 04, 2006
Removing
W86L488
Revision 1.21