C541U_99 Datasheet, PDF (118/192 Pages) Siemens Semiconductor Group – 8-BIT CMOS MICROCONTROLLER

On-Chip Peripheral Components
C541U
Bit
SODn
Function
Start of data
USB Read action: SODn is set if the USB has read a fixed number (USBLen) of
bytes from the transmit buffer. As a result, the buffer is empty
now and the CPU can process write actions again.
USB Write action: SODn is set if the USB has written a fixed number (USBLen) of
bytes to the receive buffer. As a result, the buffer is full and the
CPU can start read actions..
In dual buffer mode bits SODn and EODn can be set simultaneously if the corresponding buffer
page is swapped.
Semiconductor Group
6-73
1999-04-01