m66291 Renesas Electronics Corporation., m66291 Datasheet - Page 84

• Manufacturer Part Number: m66291
• Description: Assp Usb2.0 Device Controller
• Manufacturer: Renesas Electronics Corporation.

M 6 6 2 9 1 G P / H P
3.2.3
R e v 1 . 0 1
(1) Buffer state and IVAL bit of the OUT buffer
Buffer State and IVAL Bit
The relation between buffer state and IVAL bit is shown in Figure 3.2 when the buffer is set to OUT (set by
the EPi_DIR bit/ISEL bit).
The single/double buffer mode is set by the EPi_DBLB bit. The double buffer mode cannot be set at endpoint 0.
2 0 0 4 . 1 1 . 0 1
Figure 3.2 Relation between Buffer State and IVAL Bit (when set to OUT buffer)
W hen set to O UT buffer
<W hen set to single buffer mode>
<W hen set to double buffer mode>
Response (Note 1)
Response (Note 1)
Note 1. Response to the host when EP0_PID/EPn_PID bits are set to "01(BUF)".
Note 2. About the receives completion, refer to the follows:
Endpoint 0
O thers endpoint 0
p a g e 8 4 o f 1 2 2
ACK
ACK
NAK
NAK
NAK
NAK
ACK
ACK
ACK
NAK
ACK
ACK
NAK
ACK
ACK
ACK
CTRW bit of Control Transfer Control Register
EPnRW MD bit of EPn Configuration Register
Receiv e com pletion (Note 2)
SIE bus
SIE bus
Receive com pletion (Note 2)
Receiv e com pletion (Note 2)
SIE side buffer
SIE side buffer CPU side buffer
Receive data
Receive data
Receive data
Receive
Receive
Receive
data
data
data
Empty
Empty
Empty
Empty
Empty
Empty
Empty
Read com pletion
Read com pletion
CPU side buffer
Read com pletion
Receive data
Receive data
Receive data
Empty
Empty
Empty
Empty
Empty
Empty
Receive
Receive
Receive
data
data
data
CPU bus
CPU bus
IVAL bit ="0"
IVAL bit ="0"
IVAL bit ="0"
IVAL bit ="1"
(EPB_RDY bit is set to "1")
IVAL bit ="1"
IVAL bit ="0"
IVAL bit ="0"
IVAL bit ="0"
IVAL bit ="0"
IVAL bit ="0"
IVAL bit ="1"
(EPB_RDYbit is set to"1")
IVAL bit ="1"
IVAL bit ="0"
IVAL bit ="1"
(EPB_RDY bit is set to "1")
IVAL bit ="1"
IVAL bit ="0"
Accessable
Not accessable