Semiconductor chip and semiconductor device including the same
A semiconductor chip includes a plurality of pads; input/output circuits connected with the plurality of pads, respectively; a product data storage section configured to store a product data; and a setting section configured to set to an active state, each of the input circuits which is connected to one of the plurality of pads used for input to an internal circuit, and each of the output circuits which is connected to one of the plurality of pads used for output from the internal circuit, and set remaining input/output circuits to an inactive state, based on the product data.
1. A method of controlling a semiconductor device, said semiconductor device comprising a plurality of pads, input circuits each connected with a respective one of said plurality of pads, and a product data storage section configured to store a product data, said method comprising:
turning on power of a semiconductor device;
decoding said product data to output a control signal on at least one control line;
setting a part of input circuits to an active state and a remaining part to an inactive state, in response to said control signal, whereby pads associated with the remaining part of said input circuits are prevented from being in a floating state; and
transferring input signals supplied to pads connected with the part of said input circuits into an internal circuit.
2. The method according to claim 1 , wherein said setting comprises:
setting a part of output circuits to an active state and a remaining part to an inactive state, in response to said control signal.
3. The method according to claim 1 , wherein when a reset operation is carried out, said decoding is carried out.
4. The method according to claim 1 , wherein said product data is invisible to a user.
5. The method according to claim 1 , wherein said product data contains a data indicating a number of external pins of a package on which said semiconductor chip is installed.
6. The method according to claim 5 , wherein said product data storage section comprises a nonvolatile memory, in which said product data is written in a test of said semiconductor chip.
7. The method according to claim 1 , wherein said product data storage section stores said product data prior to shipment.
8. The method according to claim 1 , wherein said setting step comprises:
outputting a control signal on one of a plurality of control lines based on product data stored in said product data storage section, each of said plurality of control lines corresponding to a respective kind of package on which said semiconductor chip is to be installed, such that said input/output circuits corresponding to a specific package on which said semiconductor chip is actually installed are activated.
9. The method according to claim 8 , wherein each of said input circuits comprises:
an input buffer circuit connected to at least one of said plurality of control lines, and
said input buffer circuit is set to the active state when said control signal is received from the connected line, and to the inactive state when said control signal is not received.
10. The method according to claim 9 , wherein said each input circuit further comprises a termination circuit, and
said termination circuit outputs a signal with a predetermined level to the internal circuit when said input circuit is set to the inactive state.
11. The method according to claim 1 , wherein said input/output circuits set to the active state are substantially uniformly arranged around a periphery of said semiconductor chip in each package.