VV6411 STMicroelectronics, VV6411 Datasheet - Page 22

• Manufacturer Part Number: VV6411
• Description: DUAL-MODE DIGITAL CAMERA CHIPSET
• Manufacturer: STMicroelectronics

STV0680B hardware interfaces
4.3.3
4.3.4
4.4
22/63
SDRAM refresh period
The SDRAM refresh period from STV0680B is guaranteed to be no greater than 15.6 S during
‘Snapshot’/self-timer/continuous/tethered video modes of operation (i.e. not standby mode). In
standby mode, the SDRAM is set to self-refresh, therefore no refresh from STV0680B takes place.
SDRAM initialisation period
The SDRAM initialisation period is currently set to 981 S in STV0680B.
USB interface
STV0680B includes a USB Version 1.1 compliant Universal Serial Bus Interface, including a
transceiver. This allows direct connection from STV0680B to a USB connector with minimal
additional hardware (i.e. a small number of passive discretes) - see
The USB interface interfaces the STV0680B to the USB at full speed 12MHz data rate. Some of the
features are:
USB drivers are supplied by ST. For USB timing information, please refer to the USB specification
V1.1.
Symbol
t
t
t
t
t
t
t
t
CK
CH
CL
AC
OH
CMS
CMH
AS
Compliant with USB protocol revision 1.1.
USB protocol handling.
USB device state handling.
Clock and data recovery from USB.
Bit stripping and bit stuffing functions.
CRC5 checking, CRC16 generation and checking.
Serial to parallel conversion.
Single bulk end point.
Min.
166.45
½
½
0
82.88
82.85
82.88
Table 5 : Timing parameters for SDRAM read/write
Max
166.89
½
Units
ns
t
t
t
ns
ns
ns
ns
CK
CK
CK
Version 3.4
Symbol
t
t
t
t
t
t
t
t
DS
DH
RCD
RAS
RC
RP
RCD
AH
STV0680B + VV6444/6410/6500
Min.
81.01
83.41
1
5
7
2
1
82.76
Chapter 6
Max
5
Units
ns
ns
t
t
t
t
t
ns
CK
CK
CK
CK
CK