Datasheet

Table Of Contents
Section 15 Universal Serial Bus Interface (USB)
Page 538 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
15.3.46 USB Time Stamp Registers H, L (UTSRH, UTSRL)
UTSRH and UTSRL store the current time stamp values. The time stamp values in UTSRH and
UTSRL are modified when the SOF flag in UIFR3 is set to 1.
UTSRH combined with UTSRL can also be handled as a 16-bit register. The USB module has an
8-bit bus. The upper byte of UTSRH can be read directly, while the lower byte of UTSRL is read
through an 8-bit temporary register. Accordingly, UTSRH and UTSRL must be read in this order.
If only UTSRL is read, the read data cannot be guaranteed. In addition, note that the time stamp
automatic update function is not supported if the SOF packed has been broken even if the SOF
marker function is enabled by setting the SFME bit of UCTLR.
UTSRH
Bit Bit Name Initial Value R/W Description
7 to 3 All 0 R Reserved
These bits are always read as 0.
2 to 0 D10 to D8 All 0 R Stores time stamp D10 to D8.
UTSRL
Bit Bit Name Initial Value R/W Description
7 to 0 D7 to D0 All 0 R Stores time stamp D7 to D0.