C8051F581-IMR Silicon Labs, C8051F581-IMR Datasheet - Page 150

• Manufacturer Part Number: C8051F581-IMR
• Description: 8-bit Microcontrollers - MCU 50MIPS 128kB 8kB SPI
• Manufacturer: Silicon Labs

Specifications of C8051F581-IMR

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

C8051F58x/F59x
17. Reset Sources
Reset circuitry allows the controller to be easily placed in a predefined default condition. On entry to this
reset state, the following occur:




All SFRs are reset to the predefined values noted in the SFR detailed descriptions. The contents of internal
data memory are unaffected during a reset; any previously stored data is preserved. However, since the
stack pointer SFR is reset, the stack is effectively lost, even though the data on the stack is not altered.
The Port I/O latches are reset to 0xFF (all logic ones) in open-drain mode. Weak pullups are enabled dur-
ing and after the reset. For V
exits the reset state.
On exit from the reset state, the program counter (PC) is reset, and the system clock defaults to the inter-
nal oscillator. The Watchdog Timer is enabled with the system clock divided by 12 as its clock source. Pro-
gram execution begins at location 0x0000.
150
CIP-51 halts program execution
Special Function Registers (SFRs) are initialized to their defined reset values
External Port pins are forced to a known state
Interrupts and timers are disabled.
Px.x
Px.x
System
Clock
Comparator 0
+
-
Detector
Missing
C0RSEF
Clock
(one-
shot)
Microcontroller
EN
DD
Extended Interrupt
CIP-51
Monitor and power-on resets, the RST pin is driven low until the device
Core
Handler
Figure 17.1. Reset Sources
WDT
PCA
EN
VDD
System Reset
Supply
Monitor
+
-
Rev. 1.2
Enable
(Software Reset)
SWRSF
'0'
VDD Monitor Reset
Power On Reset
Operation
FLASH
Errant
(wired-OR)
Reset
Funnel
/RST