Changes between Version 5 and Version 6 of Internal/NoiseGenerator/Hardware/BaBo

Timestamp:

Feb 8, 2007, 2:53:31 AM (17 years ago)

Author:

anonymous

Comment:

—

Internal/NoiseGenerator/Hardware/BaBo

@@ -7 +7 @@
 == Hardware Components ==
 
+First you must upload the firmware onto the FX2. Once the firmware is ready on the FX2. Once the FX2 is programmed, it programs the FPGA by feeding it a sequence of bits or bytes that configure all the gates and datapaths and doohickeys inside.
+
  * Cypress EZ-USB FX2 - CY7C68013 USB microcontroller, which is an 8051 core with a USB2 interface
+
+Relevant documentation extraction:
+
+{{{                                       
+3.5       USB Boot Methods                                    
+During the power-up sequence, internal logic checks the I2C-
+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).
+
+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 automati-
+cally 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
+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.
+
+}}}
+
  * Xilinx XC3S400-4TQ144C FPGA
 
-First you must upload the firmware onto the FX2. Once the firmware is ready on the FX2. Once the FX2 is programmed, it programs the FPGA by feeding it a sequence of bits or bytes that configure all the gates and datapaths and doohickeys inside.
+
 
 == PCB ==