Semiconductor device and data processing system selectively operating as one of a big endian or little endian system
A semiconductor device correctly switches endian modes regardless of the current endian mode of an interface. The semiconductor device includes a switching circuit and a first register. The switching circuit switches an interface tote used in big endian or little endian mode. The first register holds control data of the switching circuit. The switching circuit sets the interface in little endian mode when first predetermined control information is supplied to the first register, and sets the interface in big endian mode when second predetermined control information is supplied to the first register. The control information can be correctly inputted without being influenced by the endian setting status.
1. A cellular phone comprising:
a data processor;
a display panel; and
a display controller driver coupled to the display panel to control the display panel and coupled to the data processor,
wherein the display controller driver comprises:
an interface adapted to receive data, an address and an endian setting command supplied from the data processor, the endian setting command being adapted to set the interface to operate as one of a big endian system or a little endian system; and
a command register adapted to store the endian setting command when the address supplied to the interface is matched to an address assigned to the endian setting command,
wherein the endian setting command includes a high-order bit portion and a low-order bit portion, the endian setting command having a value that is unchanged with respect to values of specific bit positions even if the high-order bit portion and the low-order bit portion of the endian setting command are transposed.
2. A cellular phone according to claim 1 ,
wherein the high-order bit portion of the endian setting command is 0000000X, where X is 0 when setting the little endian system, and where X is 1 when setting the big endian system, and
wherein the low-order bit portion of the endian setting command is 0000000Y, where Y is 0 when setting the little endian system, and where Y is 1 when setting the big endian system.
3. A cellular phone according to claim 1 ,
wherein the address includes a high-order bit portion and a low-order bit portion having a value that is unchanged with respect to values of specific bit positions even if the high-order bit portion and the low-order bit portion of the address are transposed.
4. A cellular phone according to claim 3 ,
wherein the high-order bit portion of the address is 00000110, and
wherein the low-order bit portion of the address is 00000110.
5. A cellular phone comprising
a data processor;
a display panel; and
a display controller driver coupled to the display panel to control the display panel and couple to the data processor,
wherein the display controller driver comprises:
an interface adapted to receive information supplied from the data processor, the information including:
an endian setting command which sets the interface to operate as one of a big endian interface or a little endian interface, and
an address which is assigned to the endian setting command; and
a command register adapted to store the endian setting command when the address is supplied from the data processor,
wherein the endian setting command includes a high-order bit portion and a low-order bit portion, the endian setting command having a value that is unchanged with respect to values of specific bit positions even if the high-order bit portion and the low-order bit portion of the endian setting command are transposed, and
wherein the address includes a high-order bit portion and a low-order bit portion, the address having a value that is unchanged with respect to values of specific bit positions even if the high-order bit portion and the low-order bit portion of the address are transposed.
6. A cellular phone according to claim 5 ,
wherein the high-order bit portion of the endian setting command is 0000000X, where X is 0 when setting the little endian interface, and where X is 1 when setting the big endian interface, and
wherein the low-order bit portion of the endian setting command is 0000000Y, where Y is 0 when setting the little endian interface, and where Y is 1 when setting the big endian interface.
7. A cellular phone according to claim 5 ,
wherein the high-order bit portion of the address is 00000110, and
wherein the low-order bit portion of the address is 00000110.
8. A cellular comprising:
a data processor;
a display panel; and
a display controller driver coupled to the display panel to control the display panel and coupled to the data processor,
wherein the display controller driver comprises:
an interface adapted to receive information supplied from the data processor, the information including:
an endian setting command which sets the interface to operate as one of a big endian interface or a little endian interface, and
an address which is assigned to the endian setting command; and
a command register adapted to store the endian setting command when the address is supplied from the data processor,
wherein the endian setting command includes a high-order bit portion and a low-order bit portion,
wherein the address includes a high-order bit portion and a low-order bit portion,
wherein the high-order bit portion of the endian setting command is 0000000X, where X is 0 when setting the little endian interface, and where X is 1 when setting the big endian interface,
wherein the low-order bit portion of the endian setting command is 0000000Y, where Y is 0 when setting the little endian interface, and where Y is 1 when setting the big endian interface,
wherein the high-order bit portion of the address is 00000110, and
wherein the low-order bit portion of the address is 00000110.