For Silicon Laboratories, Inc. C8051F021 — Port 1
Simulation support for this peripheral or feature is comprised of:
- Dialog boxes which display and allow you to change peripheral configuration.
- VTREGs (Virtual Target Registers) which support I/O with the peripheral.
These simulation capabilities are described below.
Parallel Port 1 Dialog
This dialog displays the SFR and pins of Port 1. This port may be
used as a 8-bit general purpose I/O port.
P1 represents the P1 SFR. The HEX value and value of
each bit is displayed and may be changed from this dialog.
P1MDIN configures the input mode of each pin for this
port. When P1MDIN.x=1, P1.x is configured for digital input, and
reading this port returns a logic level. The WEAKPUD bit
determines the state of the weak pull-up bit. When
P1MDIN.x=0, P1.x is configured for analog input, which disables the
weak pull-up feature.
P1MDOUT configures the output mode of each pin for this
port. When P1MDOUT.x=1, P1.x is push-pull. When P1MDOUT.x=0, P1.x
is open drain.
Pins represents the states of the pins on the simulated
MCU. You may set the level of the input pin to high (1) or low
Data Type: unsigned char
The PORTx VTREGs represent the I/O pins of the simulated
MCU for Port 0, Port 1, and so on. PORT0 represents Port 0, PORT1
represents Port 1, etc. You may read PORTx to determine the
state of the output pins of that port. For example, in the command
window, you may type,
to obtain value corresponding to the set pins of Port 0. You may
also change the input values of port pins by changing the value of
the VTREG. For example,
sets the upper four port pins of Port 1 to a value of 1 and the
lower 4 port pins to a value of 0. You may use the bitwise operators
AND(&), OR(|) and XOR(^) to change individual bits of the PORTx
VTREGs. For example:
PORT1 |= 0x01; /* Set P1.0 Pin */
PORT3 &= ~0x02; /* Clr P3.1 Pin */
PORT1 ^= 0x80; /* Toggle P1.7 Pin */