C8051T627-B-GM Silicon Labs, C8051T627-B-GM Datasheet - Page 256

• Manufacturer Part Number: C8051T627-B-GM
• Description: 8-bit Microcontrollers - MCU UBS, 64K OTP MCU
• Manufacturer: Silicon Labs

Specifications of C8051T627-B-GM

• Rohs: yes
• Core: 8051
• Processor Series: C8051T627
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 48 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 3328 B
• On-chip Adc: Yes
• Operating Supply Voltage: 1.8 V to 5.25 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: QFN-32
• Mounting Style: SMD/SMT
• Program Memory Type: EPROM

C8051T620/1/6/7 & C8051T320/1/2/3
28.2. Timer 2
Timer 2 is a 16-bit timer formed by two 8-bit SFRs: TMR2L (low byte) and TMR2H (high byte). Timer 2 may
operate in 16-bit auto-reload mode or (split) 8-bit auto-reload mode. The T2SPLIT bit (TMR2CN.3) defines
the Timer 2 operation mode.
Timer 2 may be clocked by the system clock, the system clock divided by 12, or the external oscillator
source divided by 8. The external clock mode is ideal for real-time clock (RTC) functionality, where the
internal oscillator drives the system clock while Timer 2 (and/or the PCA) is clocked by an external preci-
sion oscillator. Note that the external oscillator source divided by 8 is synchronized with the system clock.
28.2.1. 16-bit Timer with Auto-Reload
When T2SPLIT (TMR2CN.3) is zero, Timer 2 operates as a 16-bit timer with auto-reload. Timer 2 can be
clocked by SYSCLK, SYSCLK divided by 12, or the external oscillator clock source divided by 8. As the
16-bit timer register increments and overflows from 0xFFFF to 0x0000, the 16-bit value in the Timer 2
reload registers (TMR2RLH and TMR2RLL) is loaded into the Timer 2 register as shown in Figure 28.4,
and the Timer 2 High Byte Overflow Flag (TMR2CN.7) is set. If Timer 2 interrupts are enabled (if IE.5 is
set), an interrupt will be generated on each Timer 2 overflow. Additionally, if Timer 2 interrupts are enabled
and the TF2LEN bit is set (TMR2CN.5), an interrupt will be generated each time the lower 8 bits (TMR2L)
overflow from 0xFF to 0x00.
256
External Clock / 8
SYSCLK / 12
SYSCLK
T2XCLK
0
1
T
M
H
3
Figure 28.4. Timer 2 16-Bit Mode Block Diagram
M
T
3
L
CKCON
M
H
T
2
M
T
2
L
0
1
M
T
1
M
T
0
S
C
A
1
S
C
A
0
TR2
TCLK
Rev. 1.2
Overflow
TL2
TMR2RLL TMR2RLH
TMR2L
To SMBus
TMR2H
Reload
To ADC,
SMBus
T2SPLIT
TF2CEN
T2XCLK
TF2LEN
TF2H
TF2L
TR2
Interrupt