TC1796
Peripheral Units (Vol. 2 of 2)
Analog-to-Digital Converter (ADC)
User’s Manual
25-50
V2.0, 2007-07
ADC, V2.0
conversion. The contents of register SYSTAT will be overwritten if a new synchronized
conversion is requested. Status flags indicate the state (master and/or slave) of the ADC
module during the synchronized conversion.
25.1.10.1 Synchronized Injection Mode
The Synchronized Injection Mode is controlled by bit field CHCONn.SYM in the ADC
channel control register n. A synchronized conversion is always initiated by an analog
channel operating in Synchronized Injection Mode instead of a normal request. The
initiating ADC module is named as master, while the participating ADC module is named
as slave.
To initiate a synchronized conversion in both ADC modules, the analog channel
configured for Synchronized Injection Mode must be triggered by any source. If it wins
the arbitration, a synchronized conversion is initiated in both ADC modules. This means
that the control information needed for a synchronized conversion is transferred from the
master to the slave (for instance, analog channel 2 of ADC module 0 is configured for
Synchronized Injection Mode with sync-wait feature selected; then, each time this
channel is triggered and wins the arbitration, a synchronized conversion is requested.
Thus, ADC module 0 is assumed to be the master and the control information needed
for a synchronized conversion is transferred to ADC Module 1 the slave).
Note: A Channel Injection request with an active cancel-inject-repeat feature that is
requesting a Synchronized Injection does not cancel a running conversion in the
master. A Channel Injection request with an active cancel-inject-repeat feature
does not automatically set the cancel-sync-repeat mode in the Synchronized
Injection.
The Synchronized Injection Mode provides two features:
•
Sync-wait (CHCONn.SYM = 01
B
):
The synchronized start of the conversion is delayed until the currently performed
conversions in the partner (slave) and the initiating ADC module (master) are
terminated.
•
Cancel-sync-repeat (CHCONn.SYM = 10
B
):
This feature provides the ability to cancel a conversion that is currently performed in
the slave ADC module. Thus, the synchronized conversion is immediately started
after a currently performed conversion in the initiating ADC module is terminated.
Because a conversion is cancelled in the slave ADC module, the control information
is restored and will participate in arbitration again.