FlashFlex51 MCU
SST89E52RD2 / SST89E54RD2 / SST89E58RD2 / SST89E516RD2
SST89V52RD2 / SST89V54RD2 / SST89V58RD2 / SST89V516RD2
Preliminary Specifications
Serial Port Control Register (SCON)
Location
7
6
5
4
3
2
1
0
Reset Value
98H
SM0/FE
SM1
SM2
REN
TB8
RB8
TI
RI
00000000b
Symbol
Function
FE
Set SMOD0 = 1 to access FE bit.
0: No framing error
1: Framing Error. Set by receiver when an invalid stop bit is detected. This bit needs to
be cleared by software.
SM0
SM1
SMOD0 = 0 to access SM0 bit.
Serial Port Mode Bit 0
Serial Port Mode Bit 1
SM0
0
SM1
0
Mode
0
Description
Shift Register fOSC/6 (6 clock mode) or
OSC/12 (12 clock mode)
Baud Rate1
f
0
1
1
0
1
2
8-bit UART
9-bit UART
Variable
fOSC/32 or fOSC/16 (6 clock mode)
or
fOSC/64 or fOSC/32 (12 clock mode)
Variable
1
1
3
9-bit UART
1. fOSC = oscillator frequency
SM2
REN
Enables the Automatic Address Recognition feature in Modes 2 or 3. If SM2 = 1 then RI
will not be set unless the received 9th data bit (RB8) is 1, indicating an address, and
the received byte is a given or broadcast address. In Mode 1, if SM2 = 1 then RI will not
be activated unless a valid stop bit was received. In Mode 0, SM2 should be 0.
Enables serial reception.
0: to disable reception.
1: to enable reception.
TB8
RB8
TI
The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as
desired.
In Modes 2 and 3, the 9th data bit that was received. In Mode 1, if SM2 = 0, RB8 is the
stop bit that was received. In Mode 0, RB8 is not used.
Transmit interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at
the beginning of the stop bit in the other modes, in any serial transmission, Must be
cleared by software.
RI
Receive interrupt flag. Set by hardware at the end of the8th bit time in Mode 0, or
halfway through the stop bit time in the other modes, in any serial reception (except see
SM2). Must be cleared by software.
©2004 Silicon Storage Technology, Inc.
S71255-00-000
3/04
32
SST [ SILICON STORAGE TECHNOLOGY, INC ]
