Chapter 24 Cross Triggering Unit (CTU)
MPC5602P Microcontroller Reference Manual, Rev. 4
618
Freescale Semiconductor
24.4.3
ADC results
ADC results can be stored in the channel relevant standard result register and/or in one of the four FIFOs:
the different FIFOs allow to dispatch ADC results according to their type of acquisition (for example phase
currents, rotor position or ground-noise). Each FIFO has its own interrupt line and DMA request signal
(plus an individual overflow error bit in the FIFO status register). The store location is specified in the
ADC command, that is, the FIFOs are available only in CTU Control Mode. Each entry of a FIFO is
32-bits.
The size of the FIFOs are the following:
•
FIFO1 and FIFO2—16 entries (sized to avoid overflow during a full PWM period for current
acquisitions)
•
FIFO3 and FIFO4—4 entries (low acquisition rate FIFOs)
Results in each FIFO can be read by a 16-bit read transaction (only the result is read in order to minimize
the CPU load before computing on results) or by a 32-bit read transaction (both the result and the channel
number are read in order to avoid blind acquisitions), 5 bits in the upper 16 bits indicate the ADC unit (1
bit) and the channel number (4 bits). The result registers (only for the FIFOs) can be read from two
different addresses in the ADC memory map. The format of the result depends on the address from which
it is read. The available formats are:
•
Unsigned right-justified
Conversion result is unsigned right-justified data. Bits [9:0] are used for 10-bit resolution and bits
[15:10] always return zero when read.
•
Signed left-justified
Conversion result is signed left-justified data. Bit [15] is reserved for sign and is always read as
zero for this ADC, bits [14:5] are used for 10-bit resolution, and bits [4:0] always return zero when
read.
24.5
Reload mechanism
Some CTU registers are double-buffered, and the reload is controlled by a reload enable bit, as the
TGSISR_RE bit or the DFE bit, but for the most of the double-buffered registers, the reload is controlled
by the MRS occurrence, and it is synchronized with the beginning of the CTU control period.
Single sampling ADC_1 Channel 11
Not valid - force EOC to CTU
Single sampling ADC_1 Channel 12
Not valid - force EOC to CTU
Single sampling ADC_1 Channel 13
Not valid - force EOC to CTU
Single sampling ADC_1 Channel 14
Not valid - force EOC to CTU
Single sampling ADC_1 Channel 15
Not valid - force EOC to CTU
Dual sampling ADC_0 channel x / ADC_1 channel y
Not valid - force EOC to CTU
Table 24-1. ADC commands translation (continued)
Input command
Output command