Cypress EZ-USB FX3 User Manual

EZ-USB FX3 Technical Reference Manual, Document Number: 001-76074 Rev. *F 32
Introduction to EZ-USB FX3
1.4.10.1 SD/MMC Clock Stop
FX3S supports the stop clock feature, which can save power if the internal buffer is full when receiving data from the SD/
MMC/SDIO.
1.4.10.2 SD_CLK Output Clock Stop
During the data transfer, the SD_CLK clock can be enabled (on) or disabled (stopped) at any time by the internal flow control
mechanism.
SD_CLK output frequency is dynamically configurable using a clock divider from a system clock. The clock choice for the
divisor is user-configurable through a register. For example, the following frequencies may be configured:
■ 400 kHz - For the SD/MMC card initialization
■ 20 MHz - For a card with 0- to 20-MHz frequency
■ 24 MHz - For a card with 0- to 26-MHz frequency
■ 48 MHz - For a card with 0- to 52-MHz frequency (48-MHz frequency on SD_CLK is supported when the clock input to
FX3S is 19.2 MHz or 38.4 MHz)
■ 52 MHz - For a card with 0- to 52-MHz frequency (52-MHz frequency on SD_CLK is supported when the clock input to
FX3S is 26 MHz or 52 MHz)
■ 100 MHz - For a card with 0- to 100-MHz frequency If the DDR mode is selected, data is clocked on both the rising and
falling edge of the SD clock. DDR clocks run up to 52 MHz.
1.4.10.3 Card Insertion and Removal Detection
FX3S supports the following two card insertion and removal detection mechanisms:
■ Use of SD_D[3] data
■ Use of the S0S1_INS pin
1.4.10.4 Write Protection (WP)
The S0_WP/S1_WP (SD Write Protection) on S-Port is used to connect to the WP microswitch of the SD/MMC card
connector. This pin internally connects to a CPU-accessible GPIO for firmware to detect the SD card write protection.
1.4.10.5 SDIO Interrupt
The SDIO interrupt functionality is supported as specified in the SDIO specification version 2.00 (January 30, 2007).
1.4.10.6 SDIO Read-Wait Feature
FX3S supports the optional read-wait and suspend-resume features as defined in the SDIO specification version 2.00
(January 30, 2007).
1.4.10.7 Boot Options
FX3 integrates 32 KB of ROM, which contains a bootloader, allowing FX3 to load boot images from various sources. The boot
mode is selected by the configuration of the PMODE pins as shown in Table 1-3 on page 27
The FX3 boot options are:
■ Boot from USB
■ Boot from I2C
■ Boot from SPI
■ Boot from GPIF II Async ADMux mode
■ Boot from GPIF II Sync ADMux mode
■ Boot from GPIF II Async SRAM mode

Cypress EZ-USB FX3 Specifications

General

Brand	Cypress
Model	EZ-USB FX3
Category	Controller
Language	English