R8A66597BG RENESAS [Renesas Technology Corp], R8A66597BG Datasheet - Page 153

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

R8A66597FP/DFP/BG
3.9.6
3.10 SOF Interpolation Function
R e v 1 . 0 1
Table 3.26 Relation between Connection Type and Maximum of MXPS bit Setting for Isochronous Pipe
Isochronous Transfer Payload when Host Controller function is selected
When transferring a split-transaction in the isochronous pipe, set the MXPS bit to 188 bytes or less.
Split-transaction tranfers occur when a Full-Speed device that performs isochronous transfers is connected to the
Hi-Speed hub connected to the controller. Figure 3.25 shows a connection example.
Table 3.26 shows the relation between the connection type and the maximum MXPS bit settings for the isochronous
pipe.
When using the Peripheral Controller function and a receive is unsuccessful in the 1ms (Full-Speed operation) or
125us (Hi-Speed operation) interval due to SOF packet damage or loss, the SOF is interpolated by the controller
internally. The start condition of the SOF interpolation is "USBE=1", "SCKE=1" and SOF packet receive. The controller
initializes the SOF interpolation function under the following conditions.
The SOF interpolation operates according to the following specifications.
The SOF interpolation function runs in the following functions.
When an SOF packet is lost during Full-Speed operation, the FRMNUM register FRNM bit is not updated.
When a µSOF packet is lost during Hi-Speed operation, the UFRMNUM register UFRNM bit is updated.
However, when a “µFRNM=000” µSOF packet is lost, the FRNM bit is not updated. At this time, even if µSOF packets
other than the “µFRNM=000” packet are received successfully, the FRNM bit is not updated.
(1) H/W reset
(2) USB bus reset
(3) Suspend detection
(1) Frame interval (125 us or 1ms) is based on the results of the reset handshake protocol.
(2) The interpolation function does not operate until the SOF packet is received.
(3) After the first SOF packet is received, the internal clock counts 125us or 1ms at 48MHz, then interpolates.
(4) Interpolation is performed in the previous receive intervals after the 2nd and later SOF packets are received.
(5) Interpolation is not performed in the suspend state or during a USB bus reset receive.
(1) Frame number or micro-frame number update
(2) SOFR interrupt timing, µSOF lock
(3) SOF pulse output
(4) Isochronous transfer interval count
O c t 1 7 , 2 0 0 8
When the controller goes to the suspend state in Hi-Speed operation, interpolation continues after 3ms from the
last packet.
embedded in
R8A66597
USB Host
(1)
(2)
(3)
(4)
(5)
No.
Figure 3.23 Connection Example of Split-Transaction Transfer
p a g e 1 5 3 o f 1 8 3
Hi-Speed
Full-Speed
No Hub
between R8A66597
Controller and HUB
Transfer speed
transmission)
USB Cable
(Hi-Speed
Connection Type
Hi-Speed
Full-Speed
Full-Speed
Hi-Speed
Full-Speed
Hi-Speed
Transfer speed of
connected to Hub
peripheral device
Hub
tra nsmissio n)
(Full-Speed
USB cable
Maximum value
for MXPS bit
setting
1024 bytes
188 bytes
1023 bytes
1024 bytes
1023 bytes
device with Isochronous
Full-Speed Peripheral
endpoint