Sonic Alert msm80154s, msm83c154s, msm85c154hvs user manual 102, Scon

MSM80C154S/83C154S/85C154HVS

		Table 4-15 SCON
Bit	Symbol	Function
0	RI	"End of reception" flag. This is the interrupt request flag set by
		hardware when reception of one frame has been completed. The
		interrupt is generated by ORing with the T1 flag. Since the flag
		cannot be cleared by hardware, it must be cleared by software.
1	TI	"End of transmission" flag. This is the interrupt request flag set by
		hardware when transmission of one frame has been completed.
		The interrupt is generated by ORing with the RI flag.
		Since the flag cannot be cleared by hardware, it must be cleared
		by software.
2	RB8	Storage of the 9th bit of the data received during 11-bit frame
		UART mode (mode 2 or 3). When in 10-bit frame UART mode
		(mode 1), the stop bit is stored.
3	TB8	Storage of the 9th bit of the data to be sent during 11-bit frame
		UART mode (mode 2 or 3).
4	REN	Receive enable bit. Reception is not activated if REN is not set..
5	SM2	If SM2 is set when in 11-bit frame UART mode (mode 2 or 3) and
		the 9th bit of the received data is "1", the received data is accepted
		and loaded into SBUF and RB8, and the RI flag is set. If the 9th bit
		of the received data is "0", on the other hand, the received data is
		disregarded and the SBUF, RB8, and RI flags remain unchanged.
		This function is used to enable communication between
		processors in multi-processor systems.
		If SM2 is set when in 10-bit frame UART mode (mode 1) and the
		normal stop bit cannot be received (stop bit "0"), the received data
		is disregarded, and the SBUF, RB8, and RI flags remain
		unchanged. When SM2="0", however, the sent data is received
		irrespective of the "0"/"1" status of the stop bit.
		SM2 must be cleared when in I/O extension mode (mode 0).
6	SM1	Used in setting serial port operation mode. See Table 4-16.
7	SM0	Used in setting serial port operation mode. See Table 4-16.

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