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CHAPTER 6 USB CONTROLLER
Preliminary User’s Manual S14767EJ1V0UM00
427
Figure 6-15. Buffer Directory Addition Command
31
30
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20
19
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16
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12
11
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9
8
7
6
5
4
3
2
1
0
Reserved
Command
NOD
Reserved
USB Command Register (0x40)
USB Command Address Register (0x44)
specifies Number of
Buffer Directory to
be added
specifies EndPoint Number
100: Pool0
101: Pool1
110: Pool2
31
16
15
0
Address
specifies head
address of Buffer
Directory 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.
(a) If any unused Buffer Directories remain in the pool (when the RNOD field in the Pool Information Register is
set to other than 0), USB Controller adds the number in the NOD field of the command to the RNOD field of
the Pool Information Register.
(b) When the pool is empty (when the RNOD field in the Pool Information Register is 0), USB Controller loads
the value set in the NOD field of the command into the RNOD field of the Pool Information Register.
Furthermore, it loads the value written in the USB Command Address Register into the Pool Address
Register.
6.6.4 Data receive mode
USB Controller has different receive processing every EndPoint and receive mode.
The receive mode was determined by RM field (Bit20-19) in USB EP2 Control Register (Address 28H) and USB
EP4 Control Register (Address 30H). There are four kinds of receive processing.
(1)
(2)
(3)
(4)
EndPoint0, EndPoint6
EndPoint2, EndPoint4 Normal Mode
EndPoint2, EndPoint4 Assemble Mode
EndPoint2, EndPoint4 Separate Mode
Each processing explains below.