C8051F504-IM Silicon Laboratories Inc, C8051F504-IM Datasheet - Page 288

• Manufacturer Part Number: C8051F504-IM
• Description: IC 8051 MCU 32K FLASH 48-QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F50xr

Specifications of C8051F504-IM

• Program Memory Type: FLASH
• Program Memory Size: 32KB (32K x 8)
• Package / Case: 48-QFN
• Mfg Application Notes: LIN Bootloader AppNote
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 50MHz
• Connectivity: EBI/EMI, SMBus (2-Wire/I²C), CAN, LIN, SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 40
• Ram Size: 4.25K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.25 V
• Data Converters: A/D 32x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Processor Series: C8051F5x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 4.25 KB
• Interface Type: I2C/SPI/UART
• Maximum Clock Frequency: 50 MHz
• Number Of Programmable I/os: 40
• Number Of Timers: 4
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F500DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 32-ch x 12-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 336-1527 - KIT DEV FOR C8051F50X
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1519-5

C8051F50x/F51x
27.1. 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 CPS[2:0] bits in the PCA0MD reg-
ister select the timebase for the counter/timer as shown in Table 27.1.
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. Clearing the CIDL bit in the PCA0MD register allows the PCA to continue normal operation while the
CPU is in Idle mode.
288
SYSCLK/12
SYSCLK/4
Timer 0 Overflow
ECI
SYSCLK
External Clock/8
*Note: External oscillator source divided by 8 is synchronized with the system clock.
CPS2
0
0
0
0
1
1
1
C
D
L
I
W
D
E
T
PCA0MD
W
D
C
K
L
CPS1
C
P
S
2
000
001
010
011
100
101
C
P
S
1
0
0
1
1
0
0
1
C
P
S
0
C
E
F
Figure 27.2. PCA Counter/Timer Block Diagram
IDLE
CPS0
Table 27.1. PCA Timebase Input Options
C
0
1
0
1
0
1
x
F
C
R
PCA0CN
C
C
F
5
C
C
F
4
C
C
F
3
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.
Reserved.
C
C
F
2
C
C
F
1
C
C
F
0
Rev. 1.2
0
1
PCA0L
read
Snapshot
Register
PCA0H
Timebase
PCA0L
*
To SFR Bus
To PCA Modules
Overflow
CF
To PCA Interrupt System