Dtp Function - Fujitsu F2MCTM-16LX Hardware Manual

CHAPTER 17 DTP/EXTERNAL INTERRUPTS
17.4.2

DTP Function

The DTP/external interrupt has the DTP function that detects the signal of the external
peripheral device from the DTP/external interrupt pin to start the EI
DTP Function
The DTP function detects the signal level set by the detection level setting register of the DTP/external
interrupt function to start the EI
• When the EI
accepted by the CPU, the DTP function starts the EI
• When transfer of one data item is completed, the descriptor is updated and the DTP/external interrupt
request flag bit is cleared to prepare for the next request from the DTP/external interrupt pin.
• When the EI
Figure 17.4-3 Example of Interface with External Peripheral Device (when using EI
Input to INT8 pin
(DTP factor)
CPU internal operation
Peripheral
device
of external
connection
Data transfer
request
*1: This must be cancelled within three machine clocks after the start of data transfer.
2
*2: When EI OS is "peripheral function"
332
2
OS.
2
OS operation is already enabled (ICR:ISE = 1) at the point when the interrupt request is
2
OS completes transfer of all the data, control branches to the interrupt processing.
mode)
High level request (ELVR1: LB8, LA8=01
Descriptor
select and read
1
DTP factor * DTP/external
INT
interrupt
circuit
"internal memory transfer".
2
2
OS and starts data transfer.
)
B
Internal data bus
Read and
write operation*
Interrupt
request
CPU
2
(EI OS)
OS.
2
OS in Single-chip
Descriptor
renewal
2
Internal
memory