III PERIPHERAL BLOCK: INPUT/OUTPUT PORTS

Input-Port Pins

The input pins concurrently serve as the input pins for peripheral circuits, as shown in Table 9.1. Whether they are used as input ports or for peripheral circuits can be set bit-for-bit using a function select register. All pins not used for peripheral circuits can be used as general-purpose input ports that have an interrupt function.

Table 9.1 Input Pins

Pin name

I/O

Pull-up

Function

Function select bit

K50/#DMAREQ0

I

Available

Input port / High-speed DMA request 0

CFK50(D0)/K5 function select register(0x402C0)

K51/#DMAREQ1

I

Available

Input port / High-speed DMA request 1

CFK51(D1)/K5 function select register(0x402C0)

K52/#ADTRG

I

Available

Input port / AD converter trigger

CFK52(D2)/K5 function select register(0x402C0)

K53/#DMAREQ2

I

Available

Input port / High-speed DMA request 2

CFK53(D3)/K5 function select register(0x402C0)

K54/#DMAREQ3

I

Available

Input port / High-speed DMA request 3

CFK54(D4)/K5 function select register(0x402C0)

K60/AD0

I

–

Input port / AD converter input 0

CFK60(D0)/K6 function select register(0x402C3)

K61/AD1

I

–

Input port / AD converter input 1

CFK61(D1)/K6 function select register(0x402C3)

K62/AD2

I

–

Input port / AD converter input 2

CFK62(D2)/K6 function select register(0x402C3)

K63/AD3

I

–

Input port / AD converter input 3

CFK63(D3)/K6 function select register(0x402C3)

K64/AD4

I

–

Input port / AD converter input 4

CFK64(D4)/K6 function select register(0x402C3)

K65/AD5

I

–

Input port / AD converter input 5

CFK65(D5)/K6 function select register(0x402C3)

K66/AD6

I

–

Input port / AD converter input 6

CFK66(D6)/K6 function select register(0x402C3)

K67/AD7

I

–

Input port / AD converter input 7

CFK67(D7)/K6 function select register(0x402C3)

At cold start, all pins are set for input ports Kxx (function select register CFKxx = "0"). When these pins are used for the internal peripheral circuits, write "1" to CFKxx. For details on pin functions in this case, refer to the description of each peripheral circuit in this manual.

At hot start, the pins retain their state from prior to the reset.

When the ports set for A/D converter input are read, the value obtained is always "0".

Notes on Use

The input buffers of the K50 and K60 to K67 ports use AVDDE (power voltage for A/D converter) as their power source. Furthermore, the K50 pull-up resistor is connected to AVDDE. Therefore, the following precautions must be taken.

1)When using K50 and K60–K67 as general-purpose input ports, the voltage input to the port must be high level = AVDDE and low level = VSS.

2)When using VDDE as high level similar to other ports, VDDE must be the same voltage level as AVDDE. If the input VDDE level is lower than the AVDDE level, current flows in the input buffer, or if the input VDDE level is higher than the AVDDE level, current flows from the VDDE power supply to the AVDDE power supply.

3)To fix the input level externally when the port is not used, the input pin should be connected to VSS or AVDDE.

B-III-9-2

EPSON

S1C33L03 FUNCTION PART