STV0974 datasheet(20/69 Pages) STMICROELECTRONICS

20 / 69 page

20/61

STV0974

Functional description

4.5

Microprocessor interface

4.5.1

Features

● 8-bit microprocessor interface, asynchronous read/write, one address bit

● Indirect access to image sensor and coprocessor control registers

● Direct access to image data (JPEG compressed or uncompressed)

● On-chip 2048 byte image FIFO

● Interrupt request output

● 8/16/32-byte burst DMA support

● 2 Kbyte video FIFO for JPEG data and 10 Kbyte FIFO for non-JPEG data

4.5.2

Description

The STV0974 can be connected to any general purpose 8-bit microprocessor via the

microprocessor interface. This interface substitutes functionally to the YUV and I²C interfaces, i.e.

both data and control flows are handled through the interface which provides:

● access to the image data FIFO for fast transfers of scaled-down viewfinder images or full-

resolution captured and compressed image data. For host systems with DMA support, a DMA

request line is provided, as well as programmable FIFO threshold for burst operation. For other

systems, an interrupt request output line is provided.The 2048-byte FIFO allows for greater

host system latencies; to suit system requirements, the FIFO threshold is programmable.

● access to the camera subsystem configuration and control registers, through an address/data

controller core that handles the request (as in I²C mode) and finally acknowledges through the

microprocessor interface status register.

STV0974 数据表(PDF) 20 Page - STMicroelectronics