C8051F121 Silicon Laboratories Inc, C8051F121 Datasheet - Page 329

• Manufacturer Part Number: C8051F121
• Description: IC 8051 MCU FLASH 128K 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F12xr

Specifications of C8051F121

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 100MHz
• Connectivity: EBI/EMI, SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 32
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 8.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x8b, 8x12b; D/A 2x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

24.2.1. Edge-triggered Capture Mode
In this mode, a valid transition on the CEXn pin causes PCA0 to capture the value of the PCA0 counter/
timer and load it into the corresponding module's 16-bit capture/compare register (PCA0CPLn and
PCA0CPHn). The CAPPn and CAPNn bits in the PCA0CPMn register are used to select the type of transi-
tion that triggers the capture: low-to-high transition (positive edge), high-to-low transition (negative edge),
or either transition (positive or negative edge). When a capture occurs, the Capture/Compare Flag (CCFn)
in PCA0CN is set to logic 1 and an interrupt request is generated if CCF interrupts are enabled. The CCFn
bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and
must be cleared by software.
Note: The signal at CEXn must be high or low for at least 2 system clock cycles in order to be valid.
PWM16 ECOM CAPP CAPN
Table 24.2. PCA0CPM Register Settings for PCA Capture/Compare Modules
Port I/O
X
X
X
X
X
X
0
1
X = Don’t Care
X
X
X
1
1
1
1
1
Crossbar
0
1
0
0
0
0
0
1
Figure 24.4. PCA Capture Mode Diagram
CEXn
0
0
0
0
0
0
1
1
MAT
0
0
0
1
1
0
0
0
TOG
W
P
M
1
6
n
0
0
0
0
1
1
0
0
PCA0CPMn
C
O
M
E
n
Rev. 1.4
C
A
P
P
n
C
A
P
N
n
0
1
M
A
T
n
PWM ECCF
O
G
T
n
0
0
0
0
0
1
1
1
W
P
M
n
C8051F120/1/2/3/4/5/6/7
C
C
E
F
n
0
1
X
X
X
X
X
X
0
0
C
F
C
R
PCA0CN
C
C
F
5
Capture triggered by positive edge
C
C
F
4
Capture triggered by transition on
PCA
Timebase
C
C
F
3
C8051F130/1/2/3
Capture triggered by negative
16-Bit Pulse Width Modulator
C
C
8-Bit Pulse Width Modulator
F
2
C
C
F
1
PCA Interrupt
C
C
F
0
High Speed Output
Frequency Output
Capture
Operation Mode
Software Timer
edge on CEXn
PCA0CPLn
PCA0L
on CEXn
CEXn
PCA0CPHn
PCA0H
329