C8051F303-GSR Silicon Labs, C8051F303-GSR Datasheet - Page 156
C8051F303-GSR
Manufacturer Part Number
C8051F303-GSR
Description
8-bit Microcontrollers - MCU 8KB 14Pin MCU
Manufacturer
Silicon Labs
Datasheet
1.C8051F301-GSR.pdf
(178 pages)
Specifications of C8051F303-GSR
Rohs
yes
Core
8051
Processor Series
C8051
Data Bus Width
8 bit
- Current page: 156 of 178
- Download datasheet (931Kb)
C8051F300/1/2/3/4/5
16.1. PCA Counter/Timer
The 16-bit PCA counter/timer consists of two 8-bit SFRs: PCA0L and PCA0H. PCA0H is the high byte
(MSB) of the 16-bit counter/timer and PCA0L is the low byte (LSB). Reading PCA0L automatically latches
the value of PCA0H into a “snapshot” register; the following PCA0H read accesses this “snapshot” register.
Reading the PCA0L Register first guarantees an accurate reading of the entire 16-bit PCA0 counter.
Reading PCA0H or PCA0L does not disturb the counter operation. The CPS2-CPS0 bits in the PCA0MD
register select the timebase for the counter/timer as shown in Table 16.1. Note that in ‘External oscillator
source divided by 8’ mode, the external oscillator source is synchronized with the system clock,
and must have a frequency less than or equal to the system clock.
When the counter/timer overflows from 0xFFFF to 0x0000, the Counter Overflow Flag (CF) in PCA0MD is
set to logic 1 and an interrupt request is generated if CF interrupts are enabled. Setting the ECF bit in
PCA0MD to logic 1 enables the CF flag to generate an interrupt request. The CF bit is not automatically
cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by soft-
ware (Note: PCA0 interrupts must be globally enabled before CF interrupts are recognized. PCA0 inter-
rupts are globally enabled by setting the EA bit and the EPCA0 bit to logic 1). Clearing the CIDL bit in the
PCA0MD register allows the PCA to continue normal operation while the CPU is in Idle mode.
156
*Note: External oscillator source divided by 8 is synchronized with the system clock.
CPS2
SYSCLK/12
SYSCLK/4
Timer 0 Overflow
ECI
SYSCLK
External Clock/8
0
0
0
0
1
1
CPS1
C
D
L
I
W
D
T
E
0
0
1
1
0
0
PCA0MD
W
D
L
C
K
C
P
S
2
000
001
010
011
100
101
C
P
S
1
Figure 16.2. PCA Counter/Timer Block Diagram
C
P
S
0
CPS0
E
C
F
0
1
0
1
0
1
Table 16.1. PCA Timebase Input Options
IDLE
C
F
System clock divided by 12
System clock divided by 4
Timer 0 overflow
High-to-low transitions on ECI (max rate = system clock divided by 4)
System clock
External oscillator source divided by 8
C
R
PCA0CN
C
C
F
2
C
C
F
1
C
C
F
0
Rev. 2.9
0
1
PCA0L
read
Snapshot
Register
PCA0H
Timebase
PCA0L
*
To SFR Bus
To PCA Modules
Overflow
CF
To PCA Interrupt System
Related parts for C8051F303-GSR
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
KIT EVALUATION FOR CP2102
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
KIT EVAL FOR CP2103 USB TO UART
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
KIT EVAL FOR CP2201 ETH CTRLR
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DAUGHTER CARD CAP TOUCH SENSE
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
KIT STARTER CAP TOUCH SENSE
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT FOR C8051F320/F321
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEVKIT-F120/21/22/23/24/25/26/27
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT FOR C8051F310/F311
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT F220/221/226/230/231/236
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT F300/301/302/303/304/305
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT FOR C8051F330/F331
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT FOR F005/006/007
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
DEV KIT FOR F020/F021/F022/F023
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
KIT DEV FOR C8051F34X
Manufacturer:
Silicon Laboratories Inc
Datasheet:
Part Number:
Description:
KIT DEV FOR C8051F41X
Manufacturer:
Silicon Laboratories Inc
Datasheet: