2
2.0 Inputs and Timing
2.1 Reset
The Bt860/Bt861 has the following reset methods:
•
•
•
power-up reset
RESET* pin reset
software reset register bit
Power-up reset occurs when the part is powered-up. A pin reset occurs when
the RESET* pin is held low. (It is recommended that the pin be held low for a
minimum of 50 system clock cycles.) Both power-up and pin reset cause the
initialization of all chip functions, including video timing and serial programming
registers.
Writing a 1 to register bit SRESET (1B[7]) resets all serial programing
registers to their default states, listed in Section 5.0.
2.1.1 Initialization and Power-up Configuration
At power-up all registers reset to their initial values (see Section 5.0).
The state of the FIELD pin at power-up (or pin reset) determines the default
state of the PCLK_SEL register bit and the initial clock source. If the FIELD pin
is pulled high, the initial clock source is the CLKIN pin; if the FIELD pin is
pulled low, the initial clock source is from the PLL and requires a crystal at the
XTI and XTO pins. If not loaded, the FIELD pin is pulled low with the pin’s
internal pull-down resistor.
The power-up configuration is interlaced NTSC-M, 27 MHz black burst
video, as listed in the default values of the register bit map.
NOTE: To enable active video, black burst video must be turned off by setting
register bit EACTIVE (1D[1]) to 1. Other video configurations must be
programmed using the part’s serial programming interface registers.
D860DSA
Conexant
2-1
CONEXANT [ CONEXANT SYSTEMS, INC ]
