Filter
Top Products
7-13
SERIAL I/O (SIO) PORT
14:0 BV14:0 These bits constitute the BAUD_VALUE.
Use the following equations to determine the BAUD_VALUE for a given
baud rate.
Synchronous mode 0:
†
or
Asynchronous modes 1, 2, and 3:
or
Synchronous mode 4 (SCLK
x
# output):
†
For mode 0 receptions, the BAUD_VALUE must be 0002H or greater.
Otherwise, the resulting data in the receive shift register will be incorrect.
SP
x
_BAUD (Continued)
x
= 0–1 (8XC196MH)
Address:
Reset State:
1F84H, 1F8CH
0000H
The serial port baud rate
x
(SP
x
_BAUD) register selects the serial port
x
baud rate and clock source.
The most-significant bit selects the clock source. The lower 15 bits represent BAUD_VALUE, an
unsigned integer that determines the baud rate.
The maximum BAUD_VALUE is 32,767 (7FFFH). In asynchronous modes 1, 2, and 3, the minimum
BAUD_VALUE is 0000H when using XTAL1 and 0001H when using BCLK
x
. In synchronous mode 0,
the minimum BAUD_VALUE is 0001H for transmissions and 0002H for receptions. In synchronous
mode 4, the minimum BAUD_VALUE is 0001H for both transmissions and receptions.
15 8
8XC196MH CLKSRC
BV14 BV13 BV12 BV11 BV10 BV9 BV8
7 0
BV7 BV6 BV5 BV4 BV3 BV2 BV1 BV0
Bit
Number
Bit
Mnemonic
Function
Figure 7-7. Serial Port
x
Baud Rate (SP
x
_BAUD) Register (Continued)
BAUD_VALUE
F
XTAL1
Baud Rate 2×
--------------------------------------
1–=
BCLK
x
Baud Rate
----------------------------
BAUD_VALUE
F
XTAL1
Baud Rate 16×
-----------------------------------------
1–=
BCLK
x
Baud Rate 8×
--------------------------------------
BAUD_VALUE
F
XTAL1
Baud Rate 4×
--------------------------------------
1–=