III PERIPHERAL BLOCK: SERIAL INTERFACE

If an interrupt factor occurs when the IDMA request and enable bits are set to "1", IDMA is invoked. No interrupt request is generated at that point. An interrupt request is generated upon completion of the DMA transfer. The bits can also be set so as not to generate an interrupt, with only a DAM transfer performed.

For details on DMA transfer and how to control interrupts upon completion of DMA transfer, refer to "IDMA (Intelligent DMA)".

•Ch.2 and Ch.3

For Ch.2 and Ch.3, either a port input interrupt or 16-bit timer interrupt is selected, and IDMA is initialed by means of that interrupt factor.

The correspondence between IDMA channels and Serial I/F Ch.2 and Ch.3 is shown in Table 8.12.

Table 8.12 Correspondence to IDMA Channels

Serial I/F Ch.2, Ch.3 /

Port input / 16-bit timer

IDMA Ch.

T8-Ch.4, Ch.5 interrupt factor

interrupt factor

 

T8 Ch.5 UF

FPT7

31

 

Timer 2 compare A

12

T8 Ch.4 UF

FPT5

29

 

Timer 2 compare B

11

SIO Ch.3 TXD Emp.

FPT6

30

 

Timer 4 compare A

16

SIO Ch.3 RXD Full

FPT4

28

 

Timer 4 compare B

15

SIO Ch.3 RXD Err.

FPT2

3

 

Timer 3 compare A

14

SIO Ch.2 TXD Emp.

FPT3

4

 

Timer 5 compare A

18

SIO Ch.2 RXD Full

FPT1

2

 

Timer 5 compare B

17

SIO Ch.2 RXD Err.

FPT0

1

 

Timer 3 compare B

13

For example, when port input interrupts are selected, Serial I/F Ch.2 transmit buffer empty corresponds to port 3, and to IDMA Ch.4. Therefore, IDMA can be invoked by setting both IDMA request bit RP3 (D3/0x40290) and IDMA enable bit DEP3 (D3/0x40294) to "1".

High-speed DMA

•Ch.0 and Ch.1

The receive-buffer full interrupt and transmit-buffer empty interrupt factors can also invoke high-speed DMA (HSDMA).

The following shows the HSDMA channel number and trigger set-up bit corresponding to each channel:

 

 

Table 8.13 HSDMA Trigger Set-up Bits

SIF Ch.

HSDMA Ch.

Trigger set-up bits

0

0

HSD0S[3:0] (D[3:0]) / HSDMA Ch.0/1 trigger set-up register (0x40298)

1

1

HSD1S[3:0] (D[7:4]) / HSDMA Ch.0/1 trigger set-up register (0x40298)

0

2

HSD2S[3:0] (D[3:0]) / HSDMA Ch.2/3 trigger set-up register (0x40299)

1

3

HSD3S[3:0] (D[7:4]) / HSDMA Ch.2/3 trigger set-up register (0x40299)

For HSDMA to be invoked by the receive-buffer full interrupt factor, the trigger set-up bits should be set to "1010". For HSDMA to be invoked by the transmit-buffer empty interrupt factor, the trigger set-up bits should be set to "1011". Transfer conditions, etc. must also be set on the HSDMA side.

The HSDMA channel is invoked through generation of the interrupt factor. For details on HSDMA transfer, refer to "HSDMA (High-Speed DMA)".

B-III-8-26

EPSON

S1C33L03 FUNCTION PART