Setting A Transfer Request - Fujitsu FR60 Hardware Manual

CHAPTER 14 DMA CONTROLLER (DMAC)

14.3.1 Setting a Transfer Request

The following three types of transfer requests are provided to activate DMA transfer:
• External transfer request pin
• Built-in peripheral request
• Software request
Software requests can always be used regardless of the settings of other requests.
■ External Transfer Request Pin
A transfer request is generated by input to the input pin prepared for a channel.
The MB91301 series supports ch.1, ch.2 (DREQ0, DREQ1).
If the input is valid at this point, the following sources are selected depending on the settings for
the transfer type and the start source:
❍ Edge detection
If the transfer type is block, step, or burst transfer, select edge detection:
• Falling edge detection:
• Rising edge detection:
❍ Level detection
If the transfer type is demand transfer, select level detection:
• "H" level detection:
• "L" level detection:
■ Built-in Peripheral Request
A transfer request is generated by an interrupt from the built-in peripheral circuit.
For each channel, set the peripheral's interrupt by which a transfer request is generated (When
IS[4:0] of DMACA=1XXXX
The built-in peripheral request cannot be used together with an external transfer request.
Note:
Because an interrupt request used in a transfer request seems like an interrupt request to the CPU,
disable interrupts from the interrupt controller (ICR register).
408
Set with the transfer source selection register. When IS[4:0] of
DMACA=01110 .
B
Set with the transfer source selection register. When IS[4:0] of
DMACA=01111 .
B
Set with the transfer source selection register. When IS[4:0] of
DMACA= 01110 .
B
Set with the transfer source selection register. When IS[4:0] of
DMACA= 01111 .
B
.)
B