Rfu Manipulation By Sci; Figure 8.7 Rfu Interface Of Sci - Renesas H8S/2158 User Manual

8.8.4

RFU Manipulation by SCI

Figure 8.7 is a block diagram of the RFU interface in the SCI. The SCI can use the RFU for data
transmission and reception. The RFU is activated by setting the TDRE flag and the RDRF flag.
Figure 8.8 shows the operational flow for transmission. When the transmitted data is written to the
FIFO, and start of transmission is triggered (the TDRE and RDRF flags in SSR are set to 1), the
SCI issues a data transfer request to the RFU.
Figure 8.9 shows the operational flow for reception.
This LSI
SCI
RFU interface

Figure 8.7 RFU Interface of SCI

Section 8 RAM-FIFO Unit (RFU)
TxD
RxD
TSR RSR
TDR RDR
Transmit data Receive data
Data bus
RFU
On-chip RAM
Rev. 3.00 Jan 25, 2006 page 197 of 872
REJ09B0286-0300