p87c51mc2 NXP Semiconductors, p87c51mc2 Datasheet - Page 7

• Manufacturer Part Number: p87c51mc2
• Description: 80c51 8-bit Microcontroller Family With Extended Memory
• Manufacturer: NXP Semiconductors

PIN DESCRIPTIONS
2001 Apr 06
Philips Semiconductors
MNEMONIC
P0.0 - P0.7
P1.0 - P1.7
P2.0 - P2.7
P3.0 - P3.7
80C51 8-bit microcontroller family with extended memory
64KB/96KB OTP with 2KB/3KB RAM
11,13 -19
PIN NO.
43 - 36
24 - 31
2 - 9
11
13
14
15
16
17
18
19
2
3
4
5
6
7
8
9
TYPE NAME AND FUNCTION
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
O
O
O
I
I
I
I
I
I
I
Port 0: Port 0 is an open drain, bidirectional I/O port. Port 0 pins that have 1s written to
them float and can be used as high-impendance inputs. Port 0 is also the multiplexed low-
order address and data bus during accesses to external program and data memory. In this
application, it uses strong internal pull-ups when emitting 1s.
Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups on all pins. Port 1 pins
that have 1s written to them are pulled high by the internal pull-ups and can be used as
inputs. As inputs, port 1 pins that are externally pulled low will source current because of
the internal pull-ups. (Note: When SFR bit SPEN (SPCTL.6) is ’1’, the pull-ups at P1.4 and
P1.5 are disabled.)
Port 2: Port 2 is a 8-bit bidirectional I/O port with internal pull-ups. Port 2 pins that have 1s
written to them are pulled high by the internal pull-ups and can be used as inputs. As
inputs, port 2 pins that are externally being pulled low will source current because of the
internal pull-ups. (See DC Electrical Characteristics: I
address byte during fetches from external program memory and during accesses to
external data memory that use 16-bit addresses ( MOVX @ DPTR) or 23-bit addresses
(MOVX @EPTR, EMOV). In this application, it uses strong internal pull-ups when emitting
1s. During accesses to external data memory that use 8-bit addresses ( MOV @ Ri), port2
emits the contents of the P2 Special Function Register.
Note that when 23-bit address is used, address bits A16-A22 will be output to P2.0-P2.6
when ALE is High, and address bits A8-A14 are output to P2.0-P2.6 when ALE is Low.
Address bit A15 is output on P2.7 regardless of ALE.
Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 pins that have 1s
written to them are pulled high by the internal pull-ups and can be used as inputs. As
inputs, port 3 pins that are externally pulled low will source current because of the internal
pull-ups.
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P3.0
P3.1
P3.2
P3.3
P3.4
P3.5
P3.6
P3.7
T2
T2EX
ECI
CEX0
CEX1
MOSI
CEX2
SPICLK
CEX3
CEX4
RXD0
TXD0
INT0
INT1
T0
T1
WR
RD
External data memory write strobe
Timer0 external input
Timer1 external input
External data memory read strobe
Timer/Counter 2 external count input/Clockout
Timer/Counter 2 Reload/Capture/Direction Control
External Clock Input to the PCA
Capture/Compare External I/O for PCA module 0
Capture/Compare External I/O for PCA module 1 (with pull-up on
pin)
SPI Master Out/Slave In (Selected when SFR bit SPEN (SPCTL.6)
is ’1’, in which case the pull-up for this pin is disabled)
Capture/Compare External I/O for PCA module 2 (with pull-up on
pin)
SPI Clock (Selected when SFR bit SPEN (SPCTL.6) is ’1’, in which
case the pull-up for this pin is disabled)
Capture/Compare External I/O for PCA module 3
Capture/Compare External I/O for PCA module 4
Serial input port 0
Serial output port 0
External interrupt 0
External interrupt 1
7
P87C51MB2/P87C51MC2
IL
). Port 2 emits the high-order
Preliminary specification