LAN9500 Datasheet, PDF (153/213 Pages) SMSC Corporation – USB 2.0 to 10/100 Ethernet Controller Promiscuous mode

7.3.27 HS DESCRIPTOR ATTRIBUTES REGISTER (HS_ATTR)
This register is supported only by LAN9500A/LAN9500Ai.
Address:
0A0h
Size:
32 bits
LAN950x
This register sets the length values for HS descriptors that have been loaded into Descriptor RAM via the Data Port
registers. The HS 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 1: If a descriptor does not exist in Descriptor RAM, its size value must be written as 00h.
2: 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.
3: Writing to this register when an EEPROM is present is prohibited and will result in untoward operation and
unexpected results.
4: This register is protected by Reset Protection (RST_PROTECT).
Bits
Description
Type
Default
31:24 RESERVED
RO
-
23:16 HS Polling Interval (HS_POLL_INT)
R/W
04h
15:8 HS Device Descriptor Size (HS_DEV_DESC_SIZE) Note 7-17
R/W
00h
7:0 HS Configuration Descriptor Size (HS_CFG_DESC_SIZE) Note 7-18
R/W
00h
Note 7-17
Note 7-18
The only legal values are 0 and 0x12h. Writing any other values will result in untoward behavior and
unexpected results.
The only legal values are 0 and 0x12h. Writing any other values will result in untoward behavior and
unexpected results.
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DS00001875A-page 153