D12320VF25IV Datasheet, PDF (258/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 7 DMA Controller (Not Supported in the H8S/2321)
In sequential mode and idle mode, ETCR functions as a 16-bit transfer counter (with a count range
of 1 to 65,536). ETCR is decremented by 1 each time a transfer is performed, and when the count
reaches H'0000, the DTE bit in DMABCR is cleared, and transfer ends.
Repeat Mode
Transfer Number Storage (ETCRH)
Bit
: 15
14
13
12
11
10
9
8
Initial value :
*
*
*
*
*
*
*
*
R/W
: R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Transfer Counter (ETCRL)
Bit
:
7
6
5
4
3
2
1
0
Initial value :
*
*
*
*
*
*
*
*
R/W
: R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
*: Undefined
In repeat mode, ETCR functions as transfer counter ETCRL (with a count range of 1 to 256) and
transfer number storage register ETCRH. ETCRL is decremented by 1 each time a transfer is
performed, and when the count reaches H'00, ETCRL is loaded with the value in ETCRH. At this
point, MAR is automatically restored to the value it had when the count was started. The DTE bit
in DMABCR is not cleared, and so transfers can be performed repeatedly until the DTE bit is
cleared by the user.
ETCR is not initialized by a reset or in standby mode.
Rev.6.00 Sep. 27, 2007 Page 226 of 1268
REJ09B0220-0600