h8s-2161b Renesas Electronics Corporation., h8s-2161b Datasheet - Page 204

• Manufacturer Part Number: h8s-2161b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 7 Data Transfer Controller (DTC)
7.2.5
CRA is a 16-bit register that designates the number of times data is to be transferred by the DTC.
In normal mode, the entire CRA functions as a 16-bit transfer counter (1 to 65536). It is
decremented by 1 every time data is transferred, and transfer ends when the count reaches H'0000.
In repeat mode or block transfer mode, the CRA is divided into two parts; the upper 8 bits
(CRAH) and the lower 8 bits (CRAL). CRAH holds the number of transfers while CRAL
functions as an 8-bit transfer counter (1 to 256). CRAL is decremented by 1 every time data is
transferred, and the contents of CRAH are sent when the count reaches H'00.
7.2.6
CRB is a 16-bit register that designates the number of times data is to be transferred by the DTC in
block transfer mode. It functions as a 16-bit transfer counter (1 to 65536) that is decremented by 1
every time data is transferred, and transfer ends when the count reaches H'0000.
7.2.7
DTCER specifies DTC activation interrupt sources. DTCER is comprised of five registers:
DTCERA to DTCERE. The correspondence between interrupt sources and DTCE bits is shown in
table 7.1. For DTCE bit setting, use bit manipulation instructions such as BSET and BCLR.
Multiple DTC activation sources can be set at one time (only at the initial setting) by masking all
interrupts and writing data after executing a dummy read on the relevant register.
Bit
7
6
5
4
3
2
1
0
Rev. 3.00 Mar 21, 2006 page 150 of 788
REJ09B0300-0300
Bit Name
DTCE7
DTCE6
DTCE5
DTCE4
DTCE3
DTCE2
DTCE1
DTCE0
DTC Transfer Count Register A (CRA)
DTC Transfer Count Register B (CRB)
DTC Enable Registers (DTCER)
Initial Value
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
DTC Activation Enable
Setting this bit to 1 specifies a relevant interrupt source
as a DTC activation source.
[Clearing conditions]
[Holding condition]
When the DISEL bit is 0 and the specified number of
transfers have not been completed.
When data transfer has ended with the DISEL bit in
MRB set to 1.
When the specified number of transfers have ended.