Peripheral Simulation

For NXP (founded by Philips) P89LPC971 — I²C Interface

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.

I²C Interface Communication Dialog

The I²C Communication Dialog allows you to view the data sent or received on the I²C bus.

I²C Message Generator Group

• Address contains address of the sending or receiving device.
• Direction selects the direction of the message to be sent or received.
• Bytes is the length of the last message in bytes.
• Data is the message data sent or received.
• Generate starts message transmission.
• Stop suspends I²C bus communication.

To clear the message display, double-click anywhere in the message display area.

I²C Interface Hardware Dialog

The I²C Hardware Interface dialog displays all configuration options for the on-chip I²C controller. You may interactively alter and view these options using the dialog controls.

I2C_CLK VTREG
Data Type: unsigned long

The I2C_CLK VTREG specifies the clock frequency (in Hz) to use in SLAVE mode. For example:

I2C_CLK = 100000

specifies a clock frequency of 100KHz.

I2C_IN VTREG
Data Type: unsigned int

The I2C_IN VTREG contains data sent from an I²C peripheral to the simulated MCU. The following values may be written to this register:

• 0x0000-0x00FF: An address or data byte transfer.
• 0x0100: START byte. This initiates a SLAVE transmit or receive. The next byte sent is the address.
• 0xFF00: ACK.
• 0xFF01: NACK.
• 0xFFFF: IDLE or STOP condition.

I2C_OUT VTREG
Data Type: unsigned int

The I2C_OUT VTREG contains data sent from the simulated MCU to the I²C peripheral. The following values are possible:

• 0x0000-0x00FF: An address or data byte transfer.
• 0x0100: START byte. This initiates a MASTER transmit or receive. The next byte sent is the address.
• 0xFF00: ACK.
• 0xFF01: NACK.
• 0xFFFF: IDLE or STOP condition.