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CHAPTER 15 DMAC
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Bit Functions of DMAC Pin Control Register (DATCR)
[bit 21,20, 13, 12, 5, 4] LSn1, LSn0: Transfer request input detect level select
Each of these bits selects the detection level of the corresponding external transfer request
input pin DREQn as shown in Table 15.4-1.
The values of these bits are undefined after resetting.
The bits can be both read and written.
When continuous transfer mode is used, set the bits for "H" level or "L" level detection.
[bit 19, 11, 3] AKSEn
[bit 18, 10, 2] AKDEn
These bits specify the time when the transfer request acknowledgment output signal is to be
generated from the corresponding output pin and specify whether to enable the output
function of the corresponding transfer request acknowledgment output signal pin.
These bits are initialized to "00" by resetting.
The bits can be both read and written.
[bit 17, 9, 1] EPSEn
Table 15.4-1 Selection of Transfer Input Detection Levels
LSn1 LSn0 Operation control function
0 0 Detection of rising edge
0 1 Detection of falling edge
1 0 Detection of H level
1 1 Detection of L level
Table 15.4-2 Specification of Transfer Request Acknowledgment Output
AKSEn AKDEn Operation control function
0 0 Disables transfer request acknowledgment output.
0 1 Enables transfer request acknowledgment output.
1 0 Acknowledgement is output when transfer destination data is
accessed.
1 1 Enables transfer request acknowledgment output.
Acknowledgement is output when transfer source and
destination data is accessed.