ADVANCE INFORMATION
VCT 38xxA
5.7.2.1. From Standby into Normal Mode
To switch the whole TV application from standby oper-
ation into normal mode the controller has to perform
the following sequence:
– RC.RESDIS = 1, RC.DCOCLP = 1
– RC.RESOUT =1
– switch on power supply
– wait for stable power supply
– RC.SELCLK = 1, RC.I2CEN = 1
– RC.DCOCLP = 0, RC.RESOUT = 0
– wait for RC.ALI = 0 (ext. capacitor!)
– RC.RESDIS = 0
– init DMA interface
– init TPU, VDP and Audio
– init external devices
5.7.2.2. From Normal into Standby Mode
To switch the whole TV application from normal mode
into standby operation the controller has to perform the
following sequence:
– RC.DCOCLP = 1, RC.I2CEN = 0
– wait 1ms for stable 20.25MHz DCO
– RC.SELCLK = 0
– turn off power supply
– set TPU into standby mode
– SR0 = 2, SR1 = 8, SR2 = 0
5.7.3. Internal Reset Sources
The VCT 38xxA contains three internal circuits that are
able to generate a system reset: watchdog, supply
supervision, and clock supervision.
All internal resets are directed to the open drain output
of pin RESQ. Thus a “wired or” combination with exter-
nal reset sources is possible. The RESQ pin is current
limited and therefore large external capacitances may
be connected.
All internal reset sources initially set a reset request
flag. This flag activates the pull-down transistor on the
RESQ pin. An internal reset prolongation counter
starts, as soon as no internal reset source is active any
more. It counts 4096 fCPU periods (for alternative set-
tings refer to register CR) and then resets the reset
request flag, thus releasing the RESQ pin.
Micronas
91
MICRONAS [ MICRONAS ]
