Cypress CY7C68013 User Manual

CY7C68013
Document #: 38-08012 Rev. *A Page 8 of 48
3.5 USB Boot Methods
During the power-up sequence, internal logic checks the I
2
C-compatible port for the connection of an EEPROM whose first byte
is either 0xC0 or 0xC2. If found, it uses the VID/PID/DID values in the EEPROM in place of the internally stored values (0xC0),
or it boot-loads the EEPROM contents into internal RAM (0xC2). If no EEPROM is detected, FX2 enumerates using internally
stored descriptors. The default ID values for FX2 are VID/PID/DID (0x04B4, 0x8613, 0xxxyy).
Note. The I
2
C-compatible bus SCL and SDA pins must be pulled up, even if an EEPROM is not connected. Otherwise this
detection method does not work properly.
3.6 ReNumeration
™
Because the FX2’s configuration is soft, one chip can take on the identities of multiple distinct USB devices.
When first plugged into USB, the FX2 enumerates automatically and downloads firmware and USB descriptor tables over the
USB cable. Next, the FX2 enumerates again, this time as a device defined by the downloaded information. This patented two-
step process, called ReNumeration
™
, happens instantly when the device is plugged in, with no hint that the initial download step
has occurred.
Two control bits in the USBCS (USB Control and Status) register control the ReNumeration process: DISCON and RENUM. To
simulate a USB disconnect, the firmware sets DISCON to 1. To reconnect, the firmware clears DISCON to 0.
Before reconnecting, the firmware sets or clears the RENUM bit to indicate whether the firmware or the Default USB Device will
handle device requests over endpoint zero: if RENUM = 0, the Default USB Device will handle device requests; if RENUM = 1,
the firmware will.
3.7 Interrupt System
3.7.1 INT2 Interrupt Request and Enable Registers
FX2 implements an autovector feature for INT2 and INT4. There are 27 INT2 (USB) vectors, and 14 INT4 (FIFO/GPIF) vectors.
See FX2 TRM for more details.
x8x 9x Ax Bx CxDxExFx
0
IOA IOB IOC IOD SCON1 PSW ACC B
1SP EXIF
INT2CLR IOE SBUF1
2DPL0 MPAGE
INT4CLR OEA
3DPH0
OEB
4 DPL1
OEC
5 DPH1
OED
6 DPS
OEE
7PCON
8 TCON SCON0 IE IP T2CON EICON EIE EIP
9 TMOD SBUF0
ATL0AUTOPTRH1 EP2468STAT EP01STAT RCAP2L
BTL1AUTOPTRL1 EP24FIFOFLGS GPIFTRIG RCAP2H
CTH0reserved EP68FIFOFLGS TL2
DTH1AUTOPTRH2 GPIFSGLDATH TH2
E CKCON AUTOPTRL2 GPIFSGLDATLX
F reserved AUTOPTRSETUP GPIFSGLDATLNOX
Table 3-1. Default ID Values for FX2
Default VID/PID/DID
Vendor ID 0x04B4 Cypress Semiconductor
Prod ID 0xB613 EZ-USB FX2
Device release 0xXXYY Depends on revision (0x04 for Rev E)

Cypress CY7C68013 Specifications

General

Brand	Cypress
Model	CY7C68013
Category	Controller
Language	English