C8051T322-GQR Silicon Labs, C8051T322-GQR Datasheet - Page 218

• Manufacturer Part Number: C8051T322-GQR
• Description: 8-bit Microcontrollers - MCU USB-OTP-16K-LQFP32
• Manufacturer: Silicon Labs

Specifications of C8051T322-GQR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

C8051T620/621/320/321/322/323
A quick reference for typical baud rates and system clock frequencies is given in Table 26.1.
Table 26.1. Baud Rate Generator Settings for Standard Baud Rates
26.2. Data Format
UART1 has a number of available options for data formatting. Data transfers begin with a start bit (logic
low), followed by the data bits (sent LSB-first), a parity or extra bit (if selected), and end with one or two
stop bits (logic high). The data length is variable between 5 and 8 bits. A parity bit can be appended to the
data, and automatically generated and detected by hardware for even, odd, mark, or space parity. The stop
bit length is selectable between short (1 bit time) and long (1.5 or 2 bit times), and a multi-processor com-
munication mode is available for implementing networked UART buses. All of the data formatting options
can be configured using the SMOD1 register, shown in SFR Definition . Figure 26.2 shows the timing for a
UART1 transaction without parity or an extra bit enabled. Figure 26.3 shows the timing for a UART1 trans-
action with parity enabled (PE1 = 1). Figure 26.4 is an example of a UART1 transaction when the extra bit
is enabled (XBE1 = 1). Note that the extra bit feature is not available when parity is enabled, and the sec-
ond stop bit is only an option for data lengths of 6, 7, or 8 bits.
218
Target Baud
Rate (bps)
230400
115200
230400
115200
230400
115200
57600
28800
14400
57600
28800
14400
57600
28800
14400
9600
2400
1200
9600
2400
1200
9600
2400
1200
Baud Rate
Actual Baud
Rate (bps)
230769
115385
230769
115385
230769
115385
57692
28846
14388
57692
28777
14406
57554
28812
14397
9600
2400
1200
9600
2400
1200
9600
2400
1200
=
Equation 26.1. UART1 Baud Rate
-------------------------------------------------------------------------- -

65536 (SBRLH1:SBRLL1)
Baud Rate
0.16%
0.16%
0.16%
0.16%
0.08%
0.16%
0.16%
0.16%
0.08%
0.04%
0.16%
0.16%
0.08%
0.04%
0.02%
Error
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
SYSCLK
Rev. 1.1
Oscillator
Factor
Divide
10000
10000
20000
20000
40000
1250
5000
1666
2500
1666
3334
5000
104
208
416
834
104
208
416
834
416
834
208
52
(Prescaler Bits)

SB1PS[1:0]

1
-- -
2
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11

--------------------- -
Prescaler
1
SBRLH1:SBRLL1
Reload Value in
0xFFCC
0xFFCC
0xFCBF
0xFCBF
0xFFE6
0xFE5F
0xFD8F
0xF63C
0xEC78
0xFE5F
0xFB1E
0xEC78
0xD8F0
0xFE5F
0xF97D
0xF63C
0xD8F0
0xB1E0
0xFF98
0xFF30
0xFF98
0xFF30
0xFF98
0xFF30