3 receive pool settings – NEC Network Controller uPD98502 User Manual
Page 347
CHAPTER 6 USB CONTROLLER
Preliminary User’s Manual S15543EJ1V0UM
347
6.6.3 Receive pool settings
USB Controller uses three receive pools.
Pool0
For EndPoint0 (Control) and EndPoint6 (Interrupt)
Pool1
For EndPoint2 (Isochronous)
Pool2
For EndPoint4 (Bulk)
The data in each of these three pools is written into the corresponding registers.
Pool0
USB Rx Pool0 Information Register
(Address: 1000_1050H)
USB Rx Pool0 Address Register
(Address: 1000_1054H)
Pool1
USB Rx Pool1 Information Register
(Address: 1000_1058H)
USB Rx Pool1 Address Register
(Address: 1000_105CH)
Pool2
USB Rx Pool2 Information Register
(Address: 1000_1060H)
USB Rx Pool2 Address Register
(Address: 1000_1064H)
The V
R
4120A can know the current status of each pool by reading these registers.
The V
R
4120A can write values only into the Alert field of three Information Registers above. Other filed must be set
using USB Command Register and USB Command Extension Register.
The V
R
4120A adds Buffer Directories to each pool by using the USB Command Register (Address: 1000_1040H)
and the USB Command Extension Register (Address: 1000_1044H).
To add Buffer Directories to a receive pool, the V
R
4120A performs the following processing.
(1)
The V
R
4120A places the Buffer Directory to be added to the pool, and the buffer, in system memory.
When multiple Buffer Directories are to be added, they are linked in advance.
(2)
The V
R
4120A sets the start address of the Buffer Directory to be added into the link pointer to the last
Buffer Directory in the list of dependent Buffer Directories in the pool.
(3)
The V
R
4120A sets the start address of the Buffer Directory to be added into the USB Command
Extension Register (Address: 1000_1044H).
(4)
The V
R
4120A sets the pool number and size of the Buffer Directory to be added into the USB Command
Register (Address: 1000_1040H).
Figure 6-15. Buffer Directory Addition Command
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1
0
R eserv ed
C om m an d
N O D
R es erved
U S B C om m and R egister (40H )
U S B C om m and E x tension R egister (44H )
specif ies N um ber of
B uf fer D irectory to
be added
specif ies E ndP oint N um ber
100: P ool0
101: P ool1
110: P ool2
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0
A ddress
specif ies start
address of B uff er
D irec tory to be
added
The operation of USB Controller varies with whether any unused Buffer Directories remain in the corresponding
pool when the Buffer Directory addition command is written into the USB Command Register.