C8051F120/1/2/3/4/5/6/7 C8051F130/1/2/3
28
Rev. 1.4
1.1.3. Additional Features
Several key enhancements are implemented in the CIP-51 core and peripherals to improve overall perfor-
mance and ease of use in end applications.
The extended interrupt handler provides 20 interrupt sources into the CIP-51 (as opposed to 7 for the stan-
dard 8051), allowing the numerous analog and digital peripherals to interrupt the controller. An interrupt
driven system requires less intervention by the MCU, giving it more effective throughput. The extra inter-
rupt sources are very useful when building multi-tasking, real-time systems.
There are up to seven reset sources for the MCU: an on-board V
DD
monitor, a Watchdog Timer, a missing
clock detector, a voltage level detection from Comparator0, a forced software reset, the CNVSTR0 input
pin, and the RST pin. The RST pin is bi-directional, accommodating an external reset, or allowing the inter-
nally generated POR to be output on the RST pin. Each reset source except for the V
DD
monitor and Reset
Input pin may be disabled by the user in software; the V
DD
monitor is enabled/disabled via the MONEN
pin. The Watchdog Timer may be permanently enabled in software after a power-on reset during MCU ini-
tialization.
The MCU has an internal, stand alone clock generator which is used by default as the system clock after
any reset. If desired, the clock source may be switched on the fly to the external oscillator, which can use a
crystal, ceramic resonator, capacitor, RC, or external clock source to generate the system clock. This can
be extremely useful in low power applications, allowing the MCU to run from a slow (power saving) exter-
nal crystal source, while periodically switching to the 24.5 MHz internal oscillator as needed. Additionally,
an on-chip PLL is provided to achieve higher system clock speeds for increased throughput.
Figure 1.7. On-Board Clock and Reset
WDT
XTAL1
XTAL2
OSC
Internal
Clock
Generator
System
Clock
CIP-51
Microcontroller
Core
Missing
Clock
Detector
(one-
shot)
WD
T
Str
obe
Software Reset
Extended Interrupt
Handler
Clock Select
RST
+
-
V
DD
Supply
Reset
Timeout
(wired-OR)
System Reset
Supply
Monitor
PRE
Reset
Funnel
+
-
CP0+
Comparator0
CP0-
(Port I/O)
Crossbar
CNVSTR
(CNVSTR
reset
enable)
(CP0
reset
enable)
EN
WD
T
Enable
EN
M
CD
Enable
PLL
Circuitry
Summary of Contents for C8051F12 Series
Page 2: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 2 Rev 1 4 NOTES ...
Page 104: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 104 Rev 1 4 NOTES ...
Page 112: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 112 Rev 1 4 NOTES ...
Page 176: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 176 Rev 1 4 ...
Page 184: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 184 Rev 1 4 NOTES ...
Page 197: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 Rev 1 4 197 NOTES ...
Page 198: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 198 Rev 1 4 ...
Page 210: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 210 Rev 1 4 NOTES ...
Page 218: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 218 Rev 1 4 NOTES ...
Page 234: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 234 Rev 1 4 NOTES ...
Page 258: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 258 Rev 1 4 NOTES ...
Page 272: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 272 Rev 1 4 NOTES ...
Page 286: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 286 Rev 1 4 NOTES ...
Page 308: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 308 Rev 1 4 NOTES ...
Page 340: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 340 Rev 1 4 NOTES ...
Page 348: ...C8051F120 1 2 3 4 5 6 7 C8051F130 1 2 3 348 Rev 1 4 NOTES ...