Abstract: A portable information terminal capable of updating a program using a PC card, and a method for updating a program using the same, are provided. The portable information terminal is capable of updating a pre-stored program using a card in which a new program to be updated and a utility program for performing an updating operation are stored. The terminal includes a card unit for reading or writing the new program and the utility program stored in the card, a program storage unit for replacing the pre-stored program with the new program stored in the card and storing the new program, a memory for temporarily storing the new program and the utility program read by the card unit, and a controller for controlling the execution of the utility program stored in the memory so that the new program stored in the memory can be stored in the program storage unit. Thus, a program is correctly updated without an additional special device.

Abstract: A crossbar switch and a broadcast communication method for use in a parallel computer that avoids an occurrence of deadlock states caused by conflicts for use of a path by a plurality of broadcast messages. The parallel computer, in which a plurality of nodes are connected by a crossbar switch, is provided with output buffer monitoring circuits. A vacant capacity of each of the output buffers is monitored. The vacant capacity of each output buffer is monitored to ensure that it is sufficiently high to store the broadcast message. The parallel computer is also provided with a priority controller in which one of a plurality of broadcast messages is selected when they are input. The message transmission-permit signal is issued to the packet selector circuits only when the broadcast transmission-permit signals for all the output ports for transmitting the message are issued.