M38002M4 Datasheet, PDF (131/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPENDIX
3.5 List of registers
Transmit/Receive buffer register
b7 b6 b5 b4 b3 b2 b1 b0
Transmit/Receive buffer register (TB/RB) [Address : 1816]
B
Function
0 ^{A transmission data is written to or a receive data is read out}
from this buffer register.
1
• At writing : a data is written to the Transmit buffer register.
• At reading : a content of the Receive buffer register is read out.
At reset _{R W}
?
?
2
?
3
?
4
?
5
?
6
?
7
?
Note : A content of the Transmit buffer register cannot be read out.
A data cannot be written to the Receive buffer register.
Fig. 3.5.3 Structure of Transmit/Receive buffer register
Serial I/O status register
b7 b6 b5 b4 b3 b2 b1 b0
Serial I/O status reigster (SIOSTS) [Address : 1916]
B
Name
0
Transmit buffer empty flag
(TBE)
Function
0 : Buffer full
1 : Buffer empty
1 Receive buffer full flag (RBF) ^{0 : Buffer empty}
1 : Buffer full
2
Transmit shift register shift
completion flag (TSC)
0 : Transmit shift in progress
1 : Transmit shift completed
3 Overrun error flag (OE)
4 Parity error flag (PE)
0 : No error
1 : Overrun error
0 : No error
1 : Parity error
5 Framing error flag (FE)
6 Summing error flag (SE)
0 : No error
1 : Framing error
0 : (OE) (PE) (FE) = 0
1 : (OE) (PE) (FE) = 1
7 Nothing is allocated for this bit. It is a write disabled bit.
When this bit is read out, the value is “0.”
At reset _{R W}
0
!
0
!
0
!
0
!
0
!
0
!
0
!
1
!
Fig. 3.5.4 Structure of Serial I/O status register
3800 GROUP USER’S MANUAL
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