LAN9730 Datasheet, PDF (158/222 Pages) SMSC Corporation – High-Speed Inter-Chip (HSIC) USB 2.0

LAN9730/LAN9730i
6.3.28 FS DESCRIPTOR ATTRIBUTES REGISTER (FS_ATTR)
Address:
0A4h
Size:
32 bits
This register sets the length values for FS descriptors that have been loaded into Descriptor RAM via the Data Port reg-
isters. The FS Polling interval is also defined by a field within this register. The Descriptor RAM images may be used,
in conjunction with this register, to facilitate customized operation when no EEPROM is present.
Note: If a descriptor does not exist in Descriptor RAM, its size value must be written as 00h.
Note:
This register only affects system operation when an EEPROM is not present and the EEPROM Emulation
Enable (EEM) bit indicates Descriptor RAM and the Attributes Registers are to be used for descriptor pro-
cessing.
Note: Writing to this register when an EEPROM is present is prohibited and will result in untoward operation and
unexpected results.
Note: This register is protected by Reset Protection (RST_PROTECT).
Bits
31:24
23:16
15:8
7:0
Description
RESERVED
FS Polling Interval (FS_POLL_INT)
FS Device Descriptor Size (FS_DEV_DESC_SIZE) Note 6-11
FS Configuration Descriptor Size (FS_CFG_DESC_SIZE) Note 6-11
Type
RO
R/W
R/W
R/W
Default
-
01h
00h
00h
Note 6-11
The only legal values are 0 and 0x12h. Writing any other values will result in untoward behavior and
unexpected results.
DS00001946A-page 158
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