Z8C520

Zilog's Z8E520 (OTP) and Z8C520 (Masked ROM) microcontrollers are low-power Z8Plus MCUs, designed for the cost-effective implementation of USB and multiprotocol pointing devices.

For applications demanding powerful I/O capabilities, the Z8E520's input and output lines are grouped into two ports, and are configurable under software control to provide timing, status signals, or parallel I/O.

Both 8-bit and 16-bit timers, with a large number of user selectable modes, off-load the system of administering realtime tasks such as counting/timing and I/O data communications.

The microcontroller clock frequency is derived from the system clock by a programmable divider under firmware control.

The device is capable of functioning in four distinct, selectable communications modes: PS/2, RS232, GPIO (General- purpose I/O), and USB. The communications mode determines the functionality of the two special serial communications pins (PB6 and PB7). The device is placed in the required mode when firmware sets the specified mode bit in the communications control register. The firmware interface is similar in all modes. The same buffer area in RAM will accept the data to be transmitted. Up to 8 bytes may be loaded, and the data will actually be transmitted as soon as the appropriate command is issued (setting In Packet Ready in USB mode, for example).