Camas, Wash. The LH79531 from Sharp Microelectronics of the Americas is a 32-bit, ARM7-based system-on-chip (SoC) intended to provide high-end color LCD capabilities for portable multimedia devices. The 60-MHz ARM-7TDMI-based device is priced under $14 in lots of 10,000.
The part, first in a proposed series of such devices from Sharp, features a programmable color LCD controller that supports up to 1,024 x 768-pixel resolution, up to 64,000 colors and 15 gray shades. It's said to allow direct interface to supertwisted-nematic, CSTN and thin-film transistor (TFT) LCDs, as well as to Sharp's Highly Reflective TFT and DMTN panels.
Strategic marketing manager Raed Sabha said the new chip is capable of supporting "virtually all types" of monochrome and color LCDs, and it integrates the timing circuit required to drive Sharp HR-TFT displays, which are used in handheld applications.
Sabha said a 32-bit-wide bus supplies data to the LCD controller from SDRAM and a 16-bit bus is available for static memory (flash, SRAM and ROM) and peripherals. Dynamic bus sizing lets the buses operate with 16-bit and 8-bit wide memory, respectively which provides greater flexibility in memory layout.
"The dual-bus architecture eliminates the bus bandwidth bottleneck associated with single-bus systems driving high-resolution color LCD panels, especially in applications that do not lend themselves well to caching," Sabha said. "The ARM core doesn't need to concede the bus to the LCD controller, but can utilize the full bus bandwidth to maximize system performance."
The part also has a built-in programmable link loader and oscillator that generate the system and peripheral clocks from a single 32-kHz crystal. A power management function allows the chip to run in active, standby, sleep and stop modes. Customers can set the system clock frequency via the link loader and independently dial the frequency of peripherals or CPU clocks for continual power/performance trade-offs.
The part's 8 kbytes of programmable cache/SRAM, enable a processing speed of about 50 Mips, Sabha said. Integrated peripherals include a direct memory access (DMA) controller, counters/timers, a real-time clock, watchdog timer, general-purpose input/output and pulse-width modulators. A synchronous serial interface, 4-Mbit/second IrDA controller and on-chip USB interface for connecting to PCs are also included.
Samples of the part are scheduled for January availability, with production in the second quarter. A hardware development tool kit and evaluation board support packages for a number of real-time operating systems, and will be available to aid prototyping.
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EETInfo No. 616