![](http://datasheet.mmic.net.cn/30000/M32196F8UFP_datasheet_2359476/M32196F8UFP_772.png)
DIRECT RAM INTERFACE (DRI)
14
14-14
32192/32195/32196 Group Hardware Manual
Rev.1.10 REJ09B0123-0110 Apr.06.07
(2) DBST (DRI Buffer Status) bit (Bit 1)
This bit indicates whether the internal DRI buffer contains any data that has not been DRI transferred yet.
In order to avoid the data loss of Data transfer, middle buffer for 32 bits × 4 row is embedded in the inside of
DRI. If the data is in this middle buffer, DBST bit shows “1.” If it is not DBST bit shows “0”
Also, when DRST bit is “0” cleared DBST bit is cleared as well.
(3) ADST (Address Counter Status) bit (Bit 2)
This bit indicates which DRI address counter, 0 or 1, is currently selected to specify the destination address
of DRI transfer.
(4) ADMD (Address Counter Operation Mode Select) bit (Bit 3)
This bit selects operation modes of DRI address counters 0 (DRIADR0CT) and DRI address counter 1
(DRIADR1CT). Both DRI address counters operate in the same mode.
When continuous mode is selected
The active DRI address counter is incremented by 4 each time a DRI transfer is completed after DRI
transfer is enabled. In continuous mode, no DRI address reload register values are used.
When reload mode is selected
When the DCPEN (capture enable) bit in the DRI Data Capture Control Register (DRIDCAPCNT)
changes state from "0" to "1" (= enabled) after DRI transfer is enabled, the DRI address counter is
reloaded with a count value from the corresponding DRI address reload register. Thereafter, the active
DRI address counter is incremented by 4 each time a DRI transfer is completed.
Note: If the bus width for the input data from external devices is chosen to be 8 bits, a DRI transfer is
executed every four data capture events detected. Similarly, a DRI transfer is executed every two
data capture events detected if the selected bus width is 16 bits or every data capture event detected
if the selected bus width is 32 bits.
(5) ADSL (Address Counter Select) bits (Bits 4, 5)
The DRI contains two address counters to specify the internal RAM address to which data is transferred.
These bits are used to select one of the two address counters.
1) When DRI address counter 0 selected
Data is transferred to the internal RAM address specified by DRI address counter 0 (DRIADR0CT).
2) When DRI address counter 1 selected
Data is transferred to the internal RAM address specified by DRI address counter 1 (DRIADR1CT).
3) When DRI address counters 0 and 1 toggled
The DRI address counters are switched over in hardware by an event selected by the ADEV (address
counter switchover select) bit. After a mycrocomputer reset, DRI address conter 0 (DRIADR0CT) is
active. When the DRST (DRI reset) bit is cleared to "0," the active DRI address counter is initialized to
DRI address counter 0 (DRIADR0CT).
(6) ADEV (Address Counter Switchover Select) bit (Bit 7)
This bit is effective only when the ADSL (address counter select) bits are set to "10" (DRI address counters
0/1 toggled). This bit selects an event that causes the DRI address counter 0 (DRIADR0CT) and 1
(DRIADR1CT) that specify the destination address on the internal RAM of transfer to switch over.
Note: If a DEC4 underflow is selected as the address counter switchover event, it is prohibited to
select DIN4 event detection/capture event as the DEC4 count event.
14.2 DRI Related Registers