RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 12 SERIAL ARRAY UNIT
(6) Serial status register mn (SSRmn)
SSRmn is a register that indicates the communication status and error occurrence status of channel n. The errors
indicated by this register are a framing error, parity error, and overrun error.
SSRmn can be read by a 16-bit memory manipulation instruction.
The lower 8 bits of SSRmn can be set with an 8-bit memory manipulation instruction with SSRmnL.
Reset signal generation clears this register to 0000H.
Figure 12-11. Format of Serial Status Register mn (SSRmn) (1/2)
Address: F0100H, F0101H (SSR00), F0102H, F0103H (SSR01), After reset: 0000H R
F0130H, F0131H (SSR10), F0132H, F0133H (SSR11)
Symbol 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
SSRmn 0 0 0 0 0 0 0 0 0 TSF
mn
TSF
mn
0 When the STmn and SSmn bits are set to “1”
Communication is not under execution.
1 Communication is under execution.
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Feb. 22, 2013
BFF
mn
Communication status indication flag of channel n
0 0 0 PEF
mn
Because this flag is an updating flag, it is automatically cleared when the communication operation is completed.
This flag is cleared also when the STmn/SSmn bit is set to 1.
BFF
mn
0 When the STmn and SSmn bits are set to “1”
Valid data is not stored in the SDRmn register.
1 Valid data is stored in the SDRmn register.
Buffer register status indication flag of channel n
This is an updating flag. It is automatically cleared when transfer from the SDRmn register to the shift register is
completed. During reception, it is automatically cleared when data has been read from the SDRmn register. This
flag is cleared also when the STmn/SSmn bit is set to 1.
This flag is automatically set if transmit data is written to the SDRmn register when the TXEmn bit of the SCRmn
register = 1 (transmission or reception mode in each communication mode). It is automatically set if receive data is
stored in the SDRmn register when the RXEmn bit of the SCRmn register = 1 (transmission or reception mode in
each communication mode). It is also set in case of a reception error.
If data is written to the SDRmn register when BFFmn = 1, the transmit/receive data stored in the register is
discarded and an overrun error (OVFmn = 1) is detected.
Remark m: Unit number (m = 0, 1), n: Channel number (n = 0, 1)
OVF
mn