5.8
Serial EEPROM Present, First Byte is 0xB2
If, at power-on, the EZ-USB core detects an EEPROM connected to its I2C port with the
value 0xB2 at address 0; the EZ-USB core loads the EEPROM data into EZ-USB RAM.
It also sets the ReNum bit to 1, causing device requests to be fielded by the 8051 instead of
the EZ-USB core. The EEPROM data format is shown in Table 5-8.
Table 5-8. EEPROM Data Format for “B2” Load
EEPROM
Contents
Address
0
0xB2
1
Vendor ID (VID) L
Vendor ID (VID) H
Product ID (PID) L
Product ID (PID) H
Device ID (DID) L
Device ID (DID) H
Length H
2
3
4
5
6
7
8
Length L
9
StartAddr H
10
---
---
---
---
---
---
---
---
---
---
---
---
---
Last
StartAddr L
Data block
Length H
Length L
StartAddr H
StartAddr L
Data block
0x80
0x01
0x7F
0x92
00000000
The first byte tells the EZ-USB core to copy EEPROM data into RAM. The next six bytes
(1-6) are ignored (see the text box, “VID/PID/DID in a “B2” EEPROM” on page 5-11).
Page 5-10
Chapter 5. EZ-USB CPU
EZ-USB TRM v1.9
CYPRESS [ CYPRESS ]
