Laptop User Manual

PWM TIMER S3C2440A RISC MICROPROCESSOR
10-10
DMA REQUEST MODE
The PWM timer can generate a DMA request at every specific time. The timer keeps DMA request signals
(nDMA_REQ) low until the timer receives an ACK signal. When the timer receives the ACK signal, it makes the
request signal inactive. The timer, which generates the DMA request, is determined by setting DMA mode bits (in
TCFG1 register). If one of timers is configured as DMA request mode, that timer does not generate an interrupt
request. The others can generate interrupt normally.
DMA mode configuration and DMA / interrupt operation
DMA Mode DMA Request Timer0 INT Timer1 INT Timer2 INT Timer3 INT Timer4 INT
0000 No select ON ON ON ON ON
0001 Timer0 OFF ON ON ON ON
0010 Timer1 ON OFF ON ON ON
0011 Timer2 ON ON OFF ON ON
0100 Timer3 ON ON ON OFF ON
0101 Timer4 ON ON ON ON OFF
0110 No select ON ON ON ON ON
PCLK
INT4tmp
DMAreq_en
nDMA_ACK
nDMA_REQ
INT4
1 0 1
Figure 10-8. Timer4 DMA Mode Operation