GL852 USB 2.0 MTT HUB Controller
5.2.5 EEPROM Setting
GL852 replies to host commands by the default settings in the internal ROM. GL852 also offers the ability
to reply to the host according to the settings in the external EEPROM(93C46/24C02). The following table
shows the configuration of 93C46. GL852 firstly verifies the check sum after power on reset. If the check
sum is correct, GL852 will take the configuration of 93C46 as part of the descriptor contents. To prevent the
content of 93C46 from being over-written, amber LED will be disabled when 93C46 exists.
Table 5.1 - EEPROM Configuration
Unit: Byte
00
01
02
03
04
05
06
07
08
09 0A 0B 0C 0D 0E 0F
PORT
NUMBER
DEVICE
REMOVABLE
CHKSUM
VID_L
VID_H PID_L PID_H
FF
MaxPower FF FF FF FF FF FF FF
00h
10h
VENDOR
LENGTH
ꢁ
start
Vendor string (ASC II code)
Product String(ASC II code)
20h
30h
40h
50h
60h
end
PRODUCT
LENGTH
ꢁ
ꢁ
start
start
end
SERIAL
NUMBER
LENGTH
Serial Number String(ASC II code)
70h
end
Note: 1. VID_H/VID_L: high/low byte of VID value
2. PID_H/PID_L: high/low byte of PID value
3. CHKSUM: CHKSUM must equal to VID_H + VID_L + PID_H + PID_L + 1,otherwise
firmware will ignore the EEPROM settings.
4. PORT_NO: port number, value must be 1~4.
5. MaxPower : Describe the maximum power consumption, range=0Ma~500Ma .
Value -> 00H~FAH (unit = 2Ma)
6. DEVICE REMOVALBE:
PORT4
REMOVABLE
PORT3
REMOVABLE
PORT2
REMOVABLE
PORT1
REMOVABLE
-
-
-
-
0: Device attached to this port is removable.
1: Device attached to this port is non-removable.
7. VENDOR LENGTH: offset 10h contains the length of the vendor string. Values of vendor string is
contained from 11h~3Fh.
8. PRODUCT LENGTH: offset 40h contains the length of product string. Values of product string is
contained from 41h~6Fh.
9. SERIAL NUMBER LENGTH: offset 70h contains the value of serial number string. Values of serial
number string is contained after offset 71h.
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