C8051T611-GM Silicon Laboratories Inc, C8051T611-GM Datasheet - Page 200

• Manufacturer Part Number: C8051T611-GM
• Description: IC 8051 MCU 16K BYTE-PROG 28-QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051T61xr

Specifications of C8051T611-GM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 25
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: OTP
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 17x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-QFN
• Processor Series: C8051T6x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1.25 KB
• Interface Type: I2C, SPI, UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 29
• Number Of Timers: 4
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051FT610DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 21 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 336-1436-5

C8051T610/1/2/3/4/5/6/7
26.4. Watchdog Timer Mode
A programmable watchdog timer (WDT) function is available through the PCA Module 4. The WDT is used
to generate a reset if the time between writes to the WDT update register (PCA0CPH4) exceed a specified
limit. The WDT can be configured and enabled/disabled as needed by software.
With the WDTE bit set in the PCA0MD register, Module 4 operates as a watchdog timer (WDT). The Mod-
ule 4 high byte is compared to the PCA counter high byte; the Module 4 low byte holds the offset to be
used when WDT updates are performed. The Watchdog Timer is enabled on reset. Writes to some
PCA registers are restricted while the Watchdog Timer is enabled. The WDT will generate a reset
shortly after code begins execution. To avoid this reset, the WDT should be explicitly disabled (and option-
ally re-configured and re-enabled if it is used in the system).
26.4.1. Watchdog Timer Operation
While the WDT is enabled:






While the WDT is enabled, writes to the CR bit will not change the PCA counter state; the counter will run
until the WDT is disabled. The PCA counter run control bit (CR) will read zero if the WDT is enabled but
user software has not enabled the PCA counter. If a match occurs between PCA0CPH4 and PCA0H while
the WDT is enabled, a reset will be generated. To prevent a WDT reset, the WDT may be updated with a
write of any value to PCA0CPH4. Upon a PCA0CPH4 write, PCA0H plus the offset held in PCA0CPL4 is
loaded into PCA0CPH4 (See Figure 26.10).
200
PCA counter is forced on.
Writes to PCA0L and PCA0H are not allowed.
PCA clock source bits (CPS2–CPS0) are frozen.
PCA Idle control bit (CIDL) is frozen.
Module 4 is forced into software timer mode.
Writes to the Module 4 mode register (PCA0CPM4) are disabled.
PCA0CPL4
C
D
L
I
W
D
T
E
PCA0MD
W
D
C
K
L
Figure 26.10. PCA Module 4 with Watchdog Timer Enabled
PCA0CPH4
C
P
S
2
Write to
C
P
S
1
C
P
S
0
C
E
F
8-bit Adder
Enable
Adder
Enable
Rev 1.0
PCA0CPH4
Comparator
PCA0H
8-bit
Match
PCA0L Overflow
Reset