71M6521DE/71M6521FE
Energy Meter IC
DATASHEET
JANUARY 2008
MSB
SM
LSB
-
SM21
REN1
TB81
RB81
TI1
RI1
Table 16: The S1CON register
Bit
Symbol
Function
S0CON.7
SM0
These two bits set the UART0 mode:
Mode
0
Description
N/A
SM0
SM1
0
0
1
0
1
1
2
3
8-bit UART
9-bit UART
9-bit UART
0
1
1
S0CON.6
SM1
S0CON.5
S0CON.4
S0CON.3
SM20
REN0
TB80
Enables the inter-processor communication feature.
If set, enables serial reception. Cleared by software to disable reception.
The 9th transmitted data bit in Modes 2 and 3. Set or cleared by the MPU, depending
on the function it performs (parity check, multiprocessor communication etc.)
S0CON.2
S0CON.1
S0CON.0
RB80
TI0
In modes 2 and 3 it is the 9th data bit received. In Mode 1, if SM20 is 0, RB80 is the
stop bit. In mode 0 this bit is not used. Must be cleared by software
Transmit interrupt flag, set by hardware after completion of a serial transfer. Must be
cleared by software.
RI0
Receive interrupt flag, set by hardware after completion of a serial reception. Must
be cleared by software
Table 17: The S0CON Bit Functions
Bit
Symbol
Function
S1CON.7
SM
Sets the baud rate for UART1
SM
Mode
Description
Baud Rate
0
1
A
B
9-bit UART
8-bit UART
variable
variable
S1CON.5
S1CON.4
S1CON.3
SM21
REN1
TB81
Enables the inter-processor communication feature.
If set, enables serial reception. Cleared by software to disable reception.
The 9th transmitted data bit in Mode A. Set or cleared by the MPU, depending on the
function it performs (parity check, multiprocessor communication etc.)
S1CON.2
S1CON.1
S1CON.0
RB81
TI1
In Modes A and B, it is the 9th data bit received. In Mode B, if SM21 is 0, RB81 is the
stop bit. Must be cleared by software
Transmit interrupt flag, set by hardware after completion of a serial transfer. Must be
cleared by software.
RI1
Receive interrupt flag, set by hardware after completion of a serial reception. Must
be cleared by software
Table 18: The S1CON Bit Functions
Page: 24 of 101
© 2005-2008 TERIDIAN Semiconductor Corporation
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