Register Descriptions; Receive Shift Register (Scrsr1); Receive Data Register (Scrdr1) - Hitachi SH7750 Hardware Manual

15.2

Register Descriptions

15.2.1

Receive Shift Register (SCRSR1)

Bit:
R/W:
SCRSR1 is the register used to receive serial data.
The SCI sets serial data input from the RxD pin in SCRSR1 in the order received, starting with the
LSB (bit 0), and converts it to parallel data. When one byte of data has been received, it is
transferred to SCRDR1 automatically.
SCRSR1 cannot be directly read or written to by the CPU.
15.2.2

Receive Data Register (SCRDR1)

Bit:
Initial value:
R/W:
SCRDR1 is the register that stores received serial data.
When the SCI has received one byte of serial data, it transfers the received data from SCRSR1 to
SCRDR1 where it is stored, and completes the receive operation. SCRSR1 is then enabled for
reception.
Since SCRSR1 and SCRDR1 function as a double buffer in this way, it is possible to receive data
continuously.
SCRDR1 is a read-only register, and cannot be written to by the CPU.
SCRDR1 is initialized to H'00 by a power-on reset or manual reset, in standby mode, and in the
module standby state.
7 6 5
— — —
7 6 5
0 0 0
R R R
4 3 2
— — —
4 3 2
0 0 0
R R R
Rev. 6.0, 07/02, page 597 of 986
1 0
— —
1 0
0 0
R R