Cypress specifications Operating Modes, CY7C68300C/CY7C68301C CY7C68320C/CY7C68321C

CY7C68300C/CY7C68301C

CY7C68320C/CY7C68321C

Operating Modes

The different modes of operation and EEPROM information are presented in the following sections.

Operational Mode Selection Flow

During the power-up sequence, the AT2LP queries the I2C bus for an EEPROM. The AT2LP then selects a pinout configu- ration as shown below, and checks to see if ARESET# is configured for Board Manufacturing Test Mode.

•If no EEPROM is detected, the AT2LP uses the values in the factory-programmable (fused) memory space. See “Fused Memory Data” on page 19 for more information. This

is not a valid mode of operation if no factory programming has been done.

•If an EEPROM signature of 0x4D4D is found, the CY7C68300C/CY7C68301C uses the same pinout and EEPROM format as the CY7C68300A (EZ-USB AT2+).

•If an EEPROM signature of 0x534B is found, the AT2LP uses the values stored in the EEPROM to configure the USB descriptors for normal operation.

•If an EEPROM is detected, but an invalid signature is read, the AT2LP defaults into Board Manufacturing Test Mode.

Figure 10. Operational Mode Selection Flow

Check I2C Bus

Signature 0x534B?

Yes

Set

EZ-USB AT2LP

Pinout

EEPROM

Found?

Yes

No Signature 0x4D4D?

Yes

Set

EZ-USB AT2+ (CY7C68300A)

Pinout

No

Load Fused

Memory Data

(AT2LP Pinout)

VBUS_ATA_ENABLE	No
Pin HIGH?
Yes
ARESET#	No
Pin LOW?
Yes
DD7 Pin Set
HIGH
ARESET#	No
Pin HIGH?
Yes
Board Manufacturing	Normal Mass
Test Mode	Storage Mode
Document 001-05809 Rev. *A	Page 18 of 42

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