XA-G49 NXP Semiconductors, XA-G49 Datasheet - Page 29
![no-image](/images/manufacturer_photos/0/4/487/nxp_semiconductors_sml.jpg)
XA-G49
Manufacturer Part Number
XA-G49
Description
Xa 16-bit Microcontroller Family 64k Flash/2k Ram, Watchdog, 2 Uarts
Manufacturer
NXP Semiconductors
Datasheet
1.XA-G49.pdf
(42 pages)
Philips Semiconductors
2001 Jun 27
XA 16-bit microcontroller family
64K Flash/2K RAM, watchdog, 2 UARTs
SnCON
Bit Addressable
Reset Value: 00H
BIT
SnCON.5 SM2
SnCON.4 REN
SnCON.3 TB8
SnCON.2 RB8
SnCON.1 TI
SnCON.0 RI
Address:
SYMBOL FUNCTION
S0CON 420
S1CON 424
Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or 3, if SM2 is set to 1, then RI
will not be activated if the received 9th data bit (RB8) is 0. In Mode 1, if SM2=1 then RI will not be activated if a
valid stop bit was not received. In Mode 0, SM2 should be 0.
Enables serial reception. Set by software to enable reception. Clear by software to disable reception.
The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired. The TB8 bit is not
double buffered. See text for details.
In Modes 2 and 3, is 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 when another byte may be written to the UART transmitter. See text for details.
Must be cleared by software.
Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the end of the stop bit time
in the other modes (except see SM2). Must be cleared by software.
Figure 18. UART Multiprocessor Communication, Automatic Address Recognition
START
BIT
IN UART MODE 2 OR MODE 3 AND SM2 = 1:
– WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES
– WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.
D0
INTERRUPT IF REN=1, RB8=1 AND “RECEIVED ADDRESS” = “PROGRAMMED ADDRESS”
RECEIVED ADDRESS D0 TO D7
Where SM0, SM1 specify the serial port mode, as follows:
—
SM0
PROGRAMMED ADDRESS
D0
0
0
1
1
D1
Figure 16. Serial Port Control (SnCON) Register
—
D1
SM1
Figure 17. UART Framing Error Detection
0
1
0
1
D2
MSB
SM0
SM0_n
—
D2
1
1
Mode
3
D3
0
1
2
SM1
SM1_n
D3
shift register
8-bit UART
9-bit UART
9-bit UART
DATA BYTE
—
Description
1
0
D4
29
SM2
FEn
SM2_n
D4
COMPARATOR
D5
1
REN
D5
REN_n
BRn
Baud Rate
1
f
variable
f
variable
OSC
OSC
D6
/16
/32
D6
TB8
TB8_n
OEn
D7
X
D7
STINTn
RB8
RB8_n
D8
MODE 2, 3
ONLY IN
D8
SnSTAT
TI
TI_n
if 0, sets FE
STOP
BIT
RI_n
RI
LSB
SU00598
XA-G49
Preliminary data
SU00613
SnCON
SU00597C