Renesas SH7264 User Manual

 

Section 26   USB 2.0 Host/Function Module 

R01UH0134EJ0400  Rev. 4.00  

 

Page 1407 of 2108 

Sep 24, 2014 

 

 

 
SH7262 Group, SH7264 Group 

15 OVRN  0 

R/W* Overrun/Underrun 

Detection 

Status 

Indicates whether an overrun/underrun error has 
been detected in the pipe during isochronous 
transfer. 

0: No error 

1: An error occurred 

This bit can be cleared to 0 by writing 0 to the bit. 

(1) When the host controller function is selected 

This module sets this bit to 1 on any of the 
following conditions. 

  For the isochronous transfer pipe in the 

transmitting direction, the time to issue an OUT 

token comes before all the transmit data has 

been written to the FIFO buffer. 

  For the isochronous transfer pipe in the receiving 

direction, the time to issue an IN token comes 

when no FIFO buffer planes are empty. 

(2) When the function controller function is selected 

This module sets this bit to 1 on any of the 
following conditions. 

  For the isochronous transfer pipe in the 

transmitting direction, the IN token is received 

before all the transmit data has been written to 

the FIFO buffer. 

  For the isochronous transfer pipe in the receiving 

direction, the OUT token is received when no 

FIFO buffer planes are empty. 

Note: This bit is provided for debugging. The system 

should be designed so that no 
overrun/underrun should occur.