C8051F989-GUR Silicon Labs, C8051F989-GUR Datasheet - Page 182

• Manufacturer Part Number: C8051F989-GUR
• Description: 8-bit Microcontrollers - MCU 4kB 512B RAM
• Manufacturer: Silicon Labs

Specifications of C8051F989-GUR

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

C8051F99x-C8051F98x
SFR Definition 18.1. VDM0CN: VDD Supply Monitor Control
SFR Page = 0x0; SFR Address = 0xFF
18.3. External Reset
The external RST pin provides a means for external circuitry to force the device into a reset state.
Asserting an active-low signal on the RST pin generates a reset; an external pullup and/or decoupling of
the RST pin may be necessary to avoid erroneous noise-induced resets. See Table 4.4 for complete RST
pin specifications. The external reset remains functional even when the device is in the low power suspend
and sleep modes. The PINRSF flag (RSTSRC.0) is set on exit from an external reset.
18.4. Missing Clock Detector Reset
The missing clock detector (MCD) is a one-shot circuit that is triggered by the system clock. If the system
clock remains high or low for more than 100 µs, the one-shot will time out and generate a reset. After a
MCD reset, the MCDRSF flag (RSTSRC.2) will read 1, signifying the MCD as the reset source; otherwise,
182
Name
Reset
Bit
2:0
Type
7
6
5
4
3
Bit
VDDSTAT
VDDOKIE
VDMEN
VDDOK
Unused
Unused
VDMEN
Name
R/W
7
1
VDDSTAT
V
This bit turns the V
generate system resets until it is also selected as a reset source in register RST-
SRC (SFR Definition 18.2).
0: V
1: V
V
This bit indicates the current power supply status.
0: V
1: V
V
This bit indicates the current V
0: V
1: V
Read = 0b. Write = Don’t Care.
V
Enables the V
0: V
1: V
Read = 000b. Write = Don’t Care.
Varies
DD
DD
DD
DD
R
6
DD
DD
DD
DD
DD
DD
DD
DD
Supply Monitor Enable.
Supply Status.
Supply Status (Early Warning).
Early Warning Interrupt Enable.
Supply Monitor Disabled.
Supply Monitor Enabled.
is at or below the V
is above the V
is at or below the VDD
is above the VDD
Early Warning Interrupt is disabled.
Early Warning Interrupt is enabled.
VDDOK
Varies
DD
R
5
Early Warning Interrupt.
DD
supply monitor circuit on/off. The VDD Supply Monitor cannot
RST
WARN
threshold.
Rev. 1.1
RST
R
4
0
WARN
DD
threshold.
threshold.
power supply status.
VDDOKIE
threshold.
Function
R/W
3
1
R
2
0
R
1
0
R
0
0