1.3 Demo Design

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The following figure shows the top-level block diagram of the TVS design. All four channels of TVS are enabled in the design to monitor the die temperature and voltage rails. The Fabric logic captures the TVS channels outputs and sends them to UART IF through CoreUART IP.

The GUI receives TVS values per channel and decodes to display them as described:

Die Temperature

The temperature channel's 16-bit output value is represented in Kelvin and can be decoded as listed in the following table.

Table 1-2. Temperature Channel Value Decoding
Bit Number	Description
15	Reserved
[14:4]	Integer value of temperature
[3:0]	Fractional value of temperature

For example, suppose that the temperature channel's output value is 0x133B. In the binary format, the corresponding integer part is 00100110011 and the fractional part is 1011 which should be converted into decimal form as follows:

Integer part is calculated as:

(0 \times 2^{10}) + (0 \times 2^{9}) + (1 \times 2^{8}) + (0 \times 2^{7}) + (0 \times 2^{6}) + (1 \times 2^{5}) + (1 \times 2^{4}) + (0 \times 2^{3}) + (0 \times 2^{2}) + (1 \times 2^{1}) + (1 \times 2^{0}) = 307

Fractional part is calculated as:

(1 \times 2^{- 1}) + (0 \times 2^{- 2}) + (1 \times 2^{- 3}) + (1 \times 2^{- 4}) = 0.6875

So, the temperature output value 0x133B is 307.6875 K.

Voltage

The data present at the VALUE and CHANNEL outputs are valid only when the VALID output is asserted. When a channel is disabled by de-asserting the corresponding channel enable input, then the channel data present on the outputs is not valid even if the VALID output is asserted. The voltage channel's 16-bit output value is represented in millivolts (mV) and can be decoded as listed in the following table.

Table 1-3. Voltage Channel Value Decoding
Bit Number	Description
15	Signed bit
[14:3]	Integer value of voltage
[2:0]	Fractional value of voltage

For example, suppose that the voltage channel's output value is 0x385E. In the binary format, the corresponding integer part is 011100001011 and the fractional part is 110 which should be converted to its decimal form as follows:

Integer part is calculated as:

(0 \times 2^{11}) + (1 \times 2^{10}) + (1 \times 2^{9}) + (1 \times 2^{8}) + (0 \times 2^{7}) + (0 \times 2^{6}) + (0 \times 2^{5}) + (0 \times 2^{4}) + (1 \times 2^{3}) + (0 \times 2^{2}) + (1 \times 2^{1}) + (1 \times 2^{0}) = 1803

Fractional part is calculated as:

(1 \times 2^{- 1}) + (1 \times 2^{- 2}) + (0 \times 2^{- 3}) = 0.75

So, the voltage output value 0x385E is 1803.75 mV.

AN4682

1.3 Demo Design

Die Temperature

Voltage