C8051F330DK Silicon Laboratories Inc, C8051F330DK Datasheet - Page 125

• Manufacturer Part Number: C8051F330DK
• Description: DEV KIT FOR C8051F330/F331
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F330DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F33x
• Interface Type: RS-232
• Operating Supply Voltage: 7 V to 15 V
• Silicon Manufacturer: Silicon Labs
• Core Architecture: 8051
• Silicon Core Number: C8051F330
• Silicon Family Name: C8051F33x
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Silicon Laboratories C8051F330, C8051F331
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1264

14.3. General Purpose Port I/O
Port pins that remain unassigned by the Crossbar and are not used by analog peripherals can be used for
general purpose I/O. Ports2–0 are accessed through corresponding special function registers (SFRs) that
are both byte addressable and bit addressable. When writing to a Port, the value written to the SFR is
latched to maintain the output data value at each pin. When reading, the logic levels of the Port's input pins
are returned regardless of the XBRn settings (i.e., even when the pin is assigned to another signal by the
Crossbar, the Port register can always read its corresponding Port I/O pin). The exception to this is the
execution of the read-modify-write instructions that target a Port Latch register as the destination. The
read-modify-write instructions when operating on a Port SFR are the following: ANL, ORL, XRL, JBC, CPL,
INC, DEC, DJNZ and MOV, CLR or SETB, when the destination is an individual bit in a Port SFR. For
these instructions, the value of the register (not the pin) is read, modified, and written back to the SFR.
Bit7:
Bit6:
Bit5:
Bit4:
Bit3:
Bit2:
Bits1–0: PCA0ME: PCA Module I/O Enable Bits.
WEAKPUD XBARE
R/W
Bit7
WEAKPUD: Port I/O Weak Pullup Disable.
0: Weak Pullups enabled (except for Ports whose I/O are configured as analog input).
1: Weak Pullups disabled.
XBARE: Crossbar Enable.
0: Crossbar disabled.
1: Crossbar enabled.
T1E: T1 Enable
0: T1 unavailable at Port pin.
1: T1 routed to Port pin.
T0E: T0 Enable
0: T0 unavailable at Port pin.
1: T0 routed to Port pin.
ECIE: PCA0 External Counter Input Enable
0: ECI unavailable at Port pin.
1: ECI routed to Port pin.
Unused. Read = 0b. Write = don’t care.
00: All PCA I/O unavailable at Port pins.
01: CEX0 routed to Port pin.
10: CEX0, CEX1 routed to Port pins.
11: CEX0, CEX1, CEX2 routed to Port pins.
SFR Definition 14.2. XBR1: Port I/O Crossbar Register 1
R/W
Bit6
T1E
R/W
Bit5
T0E
R/W
Bit4
Rev. 1.7
ECIE
R/W
Bit3
C8051F330/1/2/3/4/5
Bit2
R
-
R/W
Bit1
PCA0ME
R/W
Bit0
SFR Address:
00000000
Reset Value
0xE2
129