Z86227

The Z86227 40-pin Low-Cost Digital Television Controller (4LDTC) introduces a new level of sophistication to single-chip architecture. The Z86227 is a member of the Z8® single-chip microcontroller family with 6 Kbytes of ROM and 236 bytes of RAM. The device is offered in a 40-pin package and is CMOS compatible. The 4LDTC offers mask programmed ROM which enables the Z8 microcontroller to be used in a high volume production application device embedded with a custom program (customer supplied program) and combines together with the Z86C27 (DTC) and Z86127 (LDTC) to provide support for high end, mid range and low end TV applications.

Zilog's 4LDTC offers fast execution, efficient use of memory, sophisticated interrupts, input/output bit manipulation capabilities, and easy hardware/software system expansion along with low cost and low power consumption. The Z86227 device provides an ideal performance and reliability solution for consumer and industrial television applications.

The Z86227 architecture is characterizedThe Z86227 architecture is characterized by utilizing Zilog's advanced Superintegration™ design methodology. The device has an 8-bit internal data path controlled by a Z8 microcontroller and On Screen Display (OSD) logic circuits and Pulse Width Modulators (PWM). On-chip peripherals include two register mapped I/O ports (Ports 2 and Port 3), interrupt control logic (one software, two external and three internal interrupts) and a standby mode recovery input port (Port 3, pin P30).

The OSD control circuits support 6 rows by 20 columns of characters. The character color of Z86227 is specified by row. One of the eight rows is assigned to show two kinds of colors for bar type displays such as volume control. The OSD is capable of displaying either low resolution (5x7 dot pattern) or high resolution (11x15 dot pattern) characters.A 14-bit PWM port provides enough voltage resolution for a voltage synthesizer tuning system. Three 6-bit PWM ports are used for controlling audio signal levels. Three 8-bit PWM ports used to vary picture levels.The 4LDTC applications demand powerful I/O capabilities. The Z86227 fulfills this with 24 pins dedicated to input or output.

These Z86227 lines are grouped into three ports, and are configurable under software control to provide timing, status signals, parallel I/O and an address/data bus for interfacing to external memory.

There are three basic address spaces available to support this wide range of configurations: Program Memory, Video RAM, and Register File. The Z86227 Register File is composed of 236 bytes of general purpose registers, two I/O Port registers, 15 control and status registers and three reserved registers.To unburden the program from coping with the real-time problems such as counting/timing and data communication, the 4LDTC offers two on-chip counter/timers with a large number of user selectable modes (Figure 1).