C8051T633-GM Silicon Laboratories Inc, C8051T633-GM Datasheet - Page 149
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C8051T633-GM
Manufacturer Part Number
C8051T633-GM
Description
IC MCU 4KB 20PIN QFN
Manufacturer
Silicon Laboratories Inc
Series
C8051T63xr
Specifications of C8051T633-GM
Core Processor
8051
Core Size
8-Bit
Speed
25MHz
Connectivity
SMBus (2-Wire/I²C), SPI, UART/USART
Peripherals
POR, PWM, WDT
Number Of I /o
17
Program Memory Size
4KB (4K x 8)
Program Memory Type
OTP
Ram Size
768 x 8
Voltage - Supply (vcc/vdd)
1.8 V ~ 3.6 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
20-QFN
Processor Series
C8051T6x
Core
8051
Data Bus Width
8 bit
Data Ram Size
768 B
Interface Type
UART, SPI, SMBus
Maximum Clock Frequency
25 MHz
Number Of Programmable I/os
17
Number Of Timers
4 x 16-bit
Operating Supply Voltage
1.8 V to 3.6 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
PK51, CA51, A51, ULINK2
Development Tools By Supplier
C8051T630DK
Minimum Operating Temperature
- 40 C
For Use With
336-1464 - KIT DEV FOR C8051T630 FAMILY
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
Details
Other names
336-1461-5
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
C8051T633-GM
Manufacturer:
Silicon
Quantity:
270
22.1. Enhanced Baud Rate Generation
The UART0 baud rate is generated by Timer 1 in 8-bit auto-reload mode. The TX clock is generated by
TL1; the RX clock is generated by a copy of TL1 (shown as RX Timer in Figure 22.2), which is not user-
accessible. Both TX and RX Timer overflows are divided by two to generate the TX and RX baud rates.
The RX Timer runs when Timer 1 is enabled, and uses the same reload value (TH1). However, an
RX Timer reload is forced when a START condition is detected on the RX pin. This allows a receive to
begin any time a START is detected, independent of the TX Timer state.
Timer 1 should be configured for Mode 2, 8-bit auto-reload (see Section “24.1.3. Mode 2: 8-bit Coun-
ter/Timer with Auto-Reload” on page 173). The Timer 1 reload value should be set so that overflows will
occur at two times the desired UART baud rate frequency. Note that Timer 1 may be clocked by one of six
sources: SYSCLK, SYSCLK/4, SYSCLK/12, SYSCLK/48, the external oscillator clock/8, or an external
input T1. For any given Timer 1 clock source, the UART0 baud rate is determined by Equation 22.1-A and
Equation 22.1-B.
Where T1
value). Timer 1 clock frequency is selected as described in Section “24. Timers” on page 169. A quick ref-
erence for typical baud rates and system clock frequencies is given in Table 22.1 through Table 22.2. The
internal oscillator may still generate the system clock when the external oscillator is driving Timer 1.
CLK
is the frequency of the clock supplied to Timer 1, and T1H is the high byte of Timer 1 (reload
Detected
Start
A)
B)
Figure 22.2. UART0 Baud Rate Logic
UartBaudRate
T1_Overflow_Rate
Equation 22.1. UART0 Baud Rate
RX Timer
Timer 1
TH1
TL1
=
Overflow
Overflow
Rev. 1.0
1
-- -
2
=
T1_Overflow_Rate
------------------------- -
256 TH1
T1
–
CLK
C8051T630/1/2/3/4/5
2
2
UART
RX Clock
TX Clock
149