st10f273m STMicroelectronics, st10f273m Datasheet - Page 17

• Manufacturer Part Number: st10f273m
• Description: 16-bit Mcu With 512 Kbyte Flash Memory And 36 Kbyte Ram
• Manufacturer: STMicroelectronics

ST10F273M
Table 1.
P4.0 –P4.7
WR/WRL
Symbol
READY/
READY
ALE
RD
Pin description (continued)
85-92
Pin
85
86
87
88
89
90
91
92
95
96
97
98
Type
I/O
I/O
I/O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
I
I
I
I
Port 4 is an 8-bit bidirectional I/O port. It is bit-wise programmable for input or
output via direction bit. Programming an I/O pin as input forces the
corresponding output driver to high impedance state. The input threshold is
selectable (TTL or CMOS). Port 4.4, 4.5, 4.6 and 4.7 outputs can be configured
as push-pull or open drain drivers.
In case of an external bus configuration, Port 4 can be used to output the
segment address lines:
P4.0
P4.1
P4.2
P4.3
P4.4
P4.5
P4.6
P4.7
External memory read strobe. RD is activated for every external instruction or
data read access.
External memory write strobe. In WR-mode this pin is activated for every
external data write access. In WRL mode this pin is activated for low byte data
write accesses on a 16-bit bus, and for every data write access on an 8-bit bus.
See WRCFG in the SYSCON register for mode selection.
Ready input. The active level is programmable. When the ready function is
enabled, the selected inactive level at this pin, during an external memory
access, will force the insertion of waitstate cycles until the pin returns to the
selected active level.
Address latch enable output. In case of use of external addressing or of
multiplexed mode, this signal is the latch command of the address lines.
A16
A17
A18
A19
A20
CAN2_RxD
SCL
A21
CAN1_RxD
CAN2_RxD
A22
CAN1_TxD
CAN2_TxD
A23
CAN2_TxD
SDA
Segment address line
Segment address line
Segment address line
Segment address line
Segment address line
CAN2: receive data input
I
Segment address line
CAN1: receive data input
CAN2: receive data input
Segment address line
CAN1: transmit data output
CAN2: transmit data output
Most significant segment address line
CAN2: transmit data output
I
2
2
C Interface: serial clock
C Interface: serial data
Function
Pin data
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