R8A66597BG RENESAS [Renesas Technology Corp], R8A66597BG Datasheet - Page 147

• Manufacturer Part Number: R8A66597BG
• Description: ASSP (USB2.0 2 Port Host/1 Port Peripheral Controller)
• Manufacturer: RENESAS [Renesas Technology Corp]

R8A66597FP/DFP/BG
3.7 Bulk Transfer (Pipes 1-5)
3.7.1
3.7.2
R e v 1 . 0 1
*1)
PING Packet Control with Host Controller Function Selected
NYET Handshake Control with Peripheral Controller Function Selected
The user can select the buffer memory usage method (single/double buffer, continuous/non-continuous transfer mode)
for the bulk transfer mode. The buffer memory size can be set up to a 2K-byte double buffer. The controller manages
the buffer memory state and automatically responds to PING packets and NYET handshakes.
OUT-direction PING packet are automatically sent by the controller. The controller starts the send-direction
transmission with the PING packet, as shown below. When an ACK handshake is received in response to the PING,
the OUT packet is sent. When a NAK or NYET is received in response to an OUT transaction, the controller returns to
the PING send status.
<<Start OUT Data Send >>
Factors for returning to the PING packet send status are the following settings: H/W reset, NYET/NAK handshake
receive, sequence toggle bit clear ( SQCLR ) and buffer clear ( ACLRM ).
Table 3.22 shows the list of responses to a token received in a bulk or control transfer. When an OUT token is received
in a bulk or control transfer and there is only enough open space for one packet in the buffer memory, the controller
sends a NYET response. However, when a short packet is received, the controller sends an ACK response instead of
a NYET response, even under these conditions.
Further response details:
NAK/STALL
(1) Sent PING packet
(2) Receive NAK handshake
(3) Send PING packet
(4) Receive ACK handshake
(5) Send OUT data packet
(6) Receive ACK handshake
(7) Send OUT data packet
(8) Receive NAK/NYET Handshake
PID Bit Set
RCV-BRDY*1: Buffer memory has enough space for 2 packets or more when OUT/PING token is received.
RCV-BRDY*2: Buffer memory has only enough space for one packet when OUT token is received
RCV-NRDY: Buffer memory has not enough space for one packet when PING token is received.
TRN-BRDY: Buffer memory has send data when IN token is received.
TRN-NRDY: Buffer memory does not have send data when IN token is received.
O c t 1 7 , 2 0 0 8
Value
...
BUF
Buffer Memory
RCV-BRDY*1
RCV-BRDY*2
RCV-BRDY*2
RCV-BRDY*2
RCV-NRDY
TRN-NRDY
TRN-BRDY
Status *1)
p a g e 1 4 7 o f 1 8 3
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Table 3.22 Response List for Received Tokens
Receive Token
IN/OUT/PING
OUT (Short)
OUT / PING
OUT/PING
SETUP
SETUP
PING
OUT
IN
IN
NAK/STALL
DATA0 / 1
Response
NYET
ACK
ACK
ACK
ACK
ACK
NAK
NAK
Receive data packet at OUT token receive
Receive data packet, notify immediate receiving
of next packet disabled
Receive data packet, notify immediate receiving
of next packet enabled
Notify receive enabled
Notify receive disabled
Send data packet
Notes
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