C8051F305-GSR Silicon Labs, C8051F305-GSR Datasheet - Page 104
C8051F305-GSR
Manufacturer Part Number
C8051F305-GSR
Description
8-bit Microcontrollers - MCU 2KB 14Pin MCU
Manufacturer
Silicon Labs
Datasheet
1.C8051F301-GSR.pdf
(178 pages)
Specifications of C8051F305-GSR
Rohs
yes
Core
8051
Processor Series
C8051
Data Bus Width
8 bit
- Current page: 104 of 178
- Download datasheet (931Kb)
C8051F300/1/2/3/4/5
12.1. Priority Crossbar Decoder
The Priority Crossbar Decoder (Figure 12.3) assigns a priority to each I/O function, starting at the top with
UART0. When a digital resource is selected, the least significant unassigned Port pin is assigned to that
resource (excluding UART0, which is always at pins 4 and 5). If a Port pin is assigned, the Crossbar skips
that pin when assigning the next selected resource. Additionally, the Crossbar will skip Port pins whose
associated bits in the XBR0 register are set. The XBR0 register allows software to skip Port pins that are to
be used for analog input or GPIO.
Important Note on Crossbar Configuration: If a Port pin is claimed by a peripheral without use of the
Crossbar, its corresponding XBR0 bit should be set. This applies to P0.0 if VREF is enabled, P0.3 and/or
P0.2 if the external oscillator circuit is enabled, P0.6 if the ADC is configured to use the external conversion
start signal (CNVSTR), and any selected ADC or Comparator inputs. The Crossbar skips selected pins as
if they were already assigned, and moves to the next unassigned pin. Figure 12.3 shows the Crossbar
Decoder priority with no Port pins skipped (XBR0 = 0x00); Figure 12.4 shows the Crossbar Decoder prior-
ity with pins 6 and 2 skipped (XBR0 = 0x44).
104
Figure 12.3. Crossbar Priority Decoder with XBR0 = 0x00
SF Signals
PIN I/O
TX0
RX0
SDA
SCL
CP0
CP0A
SYSCLK
CEX0
CEX1
CEX2
ECI
T0
T1
SF Signals
VREF
Port pin potentially available to peripheral
Special Function Signals are not assigned by the crossbar.
When these signals are enabled, the CrossBar must be
manually configured to skip their corresponding port pins.
Note: x1 refers to the XTAL1 signal; x2 refers to the XTAL2
signal.
0
0
1
0
x1
2
0
XBR0[0:7]
x2
3
0
Rev. 2.9
P0
4
0
5
0
CNVSTR
6
0
7
0
Related parts for C8051F305-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: