Datasheet
71M6533/G/H and 71M6534/H Data Sheet FDS_6533_6534_004
28 Rev 2
Table 17: The S0CON (UART0) Register (SFR 0x98)
Bit
Symbol
Function
S0CON[7] SM0
The SM0 and SM1 bits set the UART0 mode:
Mode
Description
SM0
SM1
0
N/A
0
0
1
8-bit UART
0
1
2
9-bit UART
1
0
3
9-bit UART
1
1
S0CON[6] SM1
S0CON[5]
SM20
Enables the inter-processor communication feature.
S0CON[4]
REN0
If set, enables serial reception. Cleared by software to disable reception.
S0CON[3] TB80
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] RB80
In Modes 2 and 3 it is the 9
th
data bit received. In Mode 1, SM20 is 0, RB80
is the stop bit. In mode 0, this bit is not used. Must be cleared by software.
S0CON[1] TI0
Transmit interrupt flag; set by hardware after completion of a serial transfer.
Must be cleared by software.
S0CON[0] RI0
Receive interrupt flag; set by hardware after completion of a serial reception.
Must be cleared by software.
Table 18: The S1CON (UART1) Register (SFR 0x9B)
Bit Symbol Function
S1CON[7] SM
Sets the baud rate and mode for UART1.
SM
Mode
Description
Baud Rate
0
A
9-bit UART
variable
1
B
8-bit UART
variable
S1CON[5]
SM21
Enables the inter-processor communication feature.
S1CON[4]
REN1
If set, enables serial reception. Cleared by software to disable reception.
S1CON[3] TB81
The 9
th
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] RB81
In Modes A and B, it is the 9
th
data bit received. In Mode B, if SM21 is 0,
RB81
is the stop bit. Must be cleared by software
S1CON[1] TI1
Transmit interrupt flag, set by hardware after completion of a serial transfer
.
Must be cleared by software.
S1CON[0] RI1
Receive interrupt flag, set by hardware after completion of a serial reception.
Must be cleared by software.
Table 19: PCON Register Bit Description (SFR 0x87)
Bit Symbol Function
PCON[7]
SMOD
The SMOD bit doubles the baud rate when set
PCON[6:2]
–
Not used.
PCON[1]
STOP
Stops MPU flash access and MPU peripherals including timers and UARTs
when set until an external interrupt is received.
PCON[0]
IDLE
Stops MPU flash access when set until an internal interrupt is received.