AP160

Version 0.0

4

AMIC Technology, Inc.

PIN DESCRIPTIONS

SYMBOL

TYPE

DESCRIPTIONS

VSS

I

Ground.

VCC

I

Supply voltage.

P0.0-P0.7

I/O

Port 0 is an 8-bit open drain, bidirectional I/O port. When 1s are written to port 0 pins, the pins

can be used as high-impedance inputs. Port 0 can also be configured to be the multiplexed

low-order address/data bus during accesses to external program and data memory. In this

mode, P0 has internal pullups. Port 0 also receives the code bytes during programming on-chip

OTP EPROM and outputs the code bytes during program verification. External pullups are

required during program verification.

P1.0-P1.7

I/O

Port 1 is an 8-bit bidirectional I/O port with internal pullups. The Port 1 output buffers can

sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the

internal pullups and can be used as inputs. As inputs, Port 1 pins that are externally being

pulled low will source current (

IL

I ) because of the internal pullups. In addition, P1.0 and P1.1

can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter

2 trigger input (P1.1/T2EX), respectively, as shown in the following:

T2 (P1.0): Timer/Counter 2 external count input/clockout (see Programmable Clock-Out)

T2EX (P1.1): Timer/Counter 2 Reload/Capture/Direction control.

Port 1 also receives the low-order address bytes during programming on-chip OTP EPROM

and verification.

P2.0-P2.7

I/O

Port 2 is an 8-bit bidirectional I/O port with internal pullups. The Port 2 output buffers can

sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the

internal pullups and can be used as inputs. As inputs, Port 2 pins that are externally being

pulled low will source current (

IL

I ) because of the internal pullups. Port 2 emits the high-order

address byte during fetches from external program memory and during accesses to external

data memory that use 16-bit addresses (MOVX @DPTR). In this application, Port 2 uses strong

internal pullups when emitting 1s. During accesses to external data memory that use 8-bit

addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2

also receives the high-order address bits and some control signals during programming on-chip

OTP EPROM and verification.

P3.0-P3.7

I/O

Port 3 is an 8-bit bidirectional I/O port with internal pullups. The Port 3 output buffers can

sink/source four TTL inputs.When 1s are written to Port 3 pins, they are pulled high by the

internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being

pulled low will source current (

IL

I ) because of the pullups. Port 3 also serves the functions of

various special features of the AP160, as shown below:

RXD (P3.0): Serial input port

TXD (P3.1): Serial output port

INT0 (P3.2): External interrupt

INT1 (P3.3): External interrupt

T0 (P3.4): Timer 0 external input

T1 (P3.5): Timer 1 external input

WR (P3.6): External data memory write strobe

RD (P3.7): External data memory read strobe

Port 3 also receives some control signals for programming and verification.

RST

I

Reset input. A high on this pin for two machine cycles while the oscillator is running resets the

device.