C8051F040-TB Silicon Laboratories Inc, C8051F040-TB Datasheet - Page 220

• Manufacturer Part Number: C8051F040-TB
• Description: BOARD PROTOTYPING W/C8051F040
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F040-TB

• Contents: Board
• Processor To Be Evaluated: C8051F04x
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F040
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

C8051F040/1/2/3/4/5/6/7
17.2. Ports 4 through 7
On C8051F040/2/4/6 devices, all Port pins on Ports 4 through 7 can be accessed as General-Purpose I/O
(GPIO) pins by reading and writing the associated Port Data registers (See SFR Definition 17.16, SFR
Definition 17.18, SFR Definition 17.20, and SFR Definition 17.22 located on SFR Page F), a set of SFRs
which are both bit and byte-addressable.
A Read of a Port Data register (or Port bit) will always return the logic state present at the pin itself, regard-
less of whether the Crossbar has allocated the pin for peripheral use or not. An exception to this occurs
during the execution of a read-modify-write instruction (ANL, ORL, XRL, CPL, INC, DEC, DJNZ, JBC,
CLR, SET, and the bitwise MOV operation). During the read cycle of the read-modify-write instruction, it is
the contents of the Port Data register, not the state of the Port pins themselves, which is read.
220
Bits7-0:
Bits7-0:
R/W
R/W
Bit7
Bit7
P1MDIN.[7:0]: Port 3 Input Mode Bits.
0: Port Pin is configured in Analog Input mode. The digital input path is disabled (a read from
the Port bit will always return ‘0’). The weak pullup on the pin is disabled.
1: Port Pin is configured in Digital Input mode. A read from the Port bit will return the logic
level at the Pin. The state of the weak pullup is determined by the WEAKPUD bit (XBR2.7,
see SFR Definition 17.3).
P2MDOUT.[7:0]: Port3 Output Mode Bits.
0: Port Pin output mode is configured as Open-Drain.
1: Port Pin output mode is configured as Push-Pull.
R/W
R/W
Bit6
Bit6
SFR Definition 17.15. P3MDOUT: Port3 Output Mode
SFR Definition 17.14. P3MDIN: Port3 Input Mode
R/W
R/W
Bit5
Bit5
R/W
R/W
Bit4
Bit4
Rev. 1.5
R/W
R/W
Bit3
Bit3
R/W
R/W
Bit2
Bit2
R/W
R/W
Bit1
Bit1
SFR Address:
SFR Address:
SFR Page:
SFR Page:
R/W
R/W
Bit0
Bit0
0xA7
F
0xAF
F
00000000
Reset Value
Reset Value
11111111