MMCCMB2107 Freescale, MMCCMB2107 Datasheet - Page 438

• Manufacturer Part Number: MMCCMB2107
• Manufacturer: Freescale

Specifications of MMCCMB2107

• Lead Free Status / RoHS Status: Not Compliant

Queued Analog-to-Digital Converter (QADC)
Technical Data
438
NOTE:
NOTE:
Read: Anytime except reads during stop mode are invalid
Write: Anytime except stop mode
P — Pause Bit
The P bit does not cause the queue to pause in the software controlled
modes or external gated modes.
BYP — Sample Amplifier Bypass Bit
BYP is maintained for software compatibility but has no functional
benefit to this version of the module.
IST[0:1] — Input Sample Time Field
The pause bit allows software to create subqueues within queue 1
and queue 2. The QADC performs the conversion specified by the
CCW with the pause bit set, and then the queue enters the pause
state. Another trigger event causes execution to continue from the
pause to the next CCW.
Setting the BYP field in the CCW enables the amplifier bypass mode
for a conversion and subsequently changes the timing. The initial
sample time is eliminated, reducing the potential conversion time by
two QCLKs. However, due to internal RC effects, a minimum final
sample time of four QCLKs must be allowed. When using this mode,
the external circuit should be of low source impedance. Loading
effects of the external circuitry need to be considered, since the
benefits of the sample amplifier are not present.
The IST field allows software to specify the length of the sample
window. Provision is made to vary the input sample time, through
software control, to offer flexibility in the source impedance of the
circuitry providing the QADC analog channel inputs. Longer sample
times permit more accurate A/D conversions of signals with higher
source impedances.
Table 18-9
Freescale Semiconductor, Inc.
For More Information On This Product,
Queued Analog-to-Digital Converter (QADC)
1 = Enter pause state after execution of current CCW
0 = Do not enter pause state after execution of current CCW
1 = Amplifier bypass mode enabled
0 = Amplifier bypass mode disabled
Go to: www.freescale.com
shows the four selectable input sample times.
MMC2107 – Rev. 2.0
MOTOROLA