Digi NS9750 - Manual (Page 769)

w w w . d i g i e m b e d d e d . c o m 7 4 5
U S B C o n t r o l l e r M o d u l e
Register bit assignment
Bits Access Mnemonic Reset Description
D31:04 R/W BCED 0h BulkCurrentED
BulkCurrentED is advanced to the next endpoint
descriptor after the host controller has served the present
endpoint descriptor. The host controller continues
processing the list from where it left off in the last frame.
When it reaches the end of the bulk list, the host controller
checks the ControlListFilled field (see "HcControl
register," beginning on page 727). If ControlListFIlled is
set, the host controller copies the content of
HcBulkHeadED to HcBulkCurrentED and clears the bit.
If ControlListFilled is not set, the host controller does
nothing.
The host controller driver is allowed to modify this
register only when the BulkListEnable field (see
"HcControl register," beginning on page 727) is cleared.
When BulkListEnable is set, the host control driver only
reads the instantaneous value of this register. This value
initially is set to zero to indicate the end of the bulk list.
D03:00 N/A Not used 0 Must be written to 0.
Table 434: HcBulkCurrentED register