87C196JQ Intel Corporation, 87C196JQ Datasheet - Page 6

• Manufacturer Part Number: 87C196JQ
• Description: ADVANCED 16-BIT CHMOS MICROCONTROLLER
• Manufacturer: Intel Corporation

87C196KR KQ 87C196JV JT 87C196JR JQ
PIN DESCRIPTIONS
6
P5 3 RD
P5 2 WR WRL
P5 5 BHE WRH
P5 6 READY
P5 4 SLPINT
P6 2 T1CLK
P6 3 T1DIR
PORT1 EPA0 – 7
P6 0–6 1 EPA8 – 9
PORT 0 ACH0– 7
P6 4–6 7 SSIO
PORT 2
PORT 3 and 4
Symbol
Read signal output to external memory RD is active only during external memory
reads or LSIO when not used as RD
Write and Write Low output to external memory as selected by the CCR WR will
go low for every external write while WRL will go low only for external writes
where an even byte is being written WR WRL is active during external memory
writes Also an LSIO pin when not used as WR WRL
Byte High Enable or Write High output as selected by the CCR BHE
the bank of memory that is connected to the high byte of the data bus A0
selects that bank of memory that is connectd to the low byte Thus accesses to a
16-bit wide memory can be to the low byte only (A0
byte only (A0
function is selected the pin will go low if the bus cycle is writing to an odd memory
location BHE WRH is only valid during 16-bit external memory write cycles Also
an LSIO pin when not BHE WRH
Ready input to lengthen external memory cycles for interfacing with slow or
dynamic memory or for bus sharing If the pin is high CPU operation continues in
a normal manner If the pin is low prior to the falling edge of CLKOUT the memory
controller goes into a wait state mode until the next positive transition in CLKOUT
occurs with READY high When external memory is not used READY has no
effect The max number of wait states inserted into the bus cycle is controlled by
the CCR CCR1 Also an LSIO pin when READY is not selected
Dual functional I O pin As a bidirectional port pin or as a system function The
system function is a Slave Port Interrupt Output Pin
Dual function I O pin Primary function is that of a bidirectional I O pin however it
may also be used as a TIMER1 Clock input The TIMER1 will increment or
decrement on both positive and negative edges of this pin
Dual function I Opin Primary function is that of a bidirectional I O pin however it
may also be used as a TIMER1 Direction input The TIMER1 will increment when
this pin is high and decrements when this pin is low
Dual function I O port pins Primary function is that of bidirectional I O System
function is that of High Speed capture and compare EPA0 and EPA2 have yet
another function of T2CLK and T2DIR of the TIMER2 timer counter
8-bit high impedance input-only port These pins can be used as digital inputs
and or as analog inputs to the on-chip A D converter These pins are also used
as inputs to EPROM parts to select the Programming Mode
Dual function I O ports that have a system function as Synchronous Serial I O
Two pins are clocks and two pins are data providing full duplex capability
8-bit multi-functional port All of its pins are shared with other functions
8-bit bidirectional I O ports with open drain outputs These pins are shared with
the multiplexed address data bus which has strong internal pullups
(Continued)
e
1 BHE
e
0) or both bytes (A0
Name and Function
e
0 BHE
e
0 BHE
e
0) If the WRH
e
1) to the high
e
0 selects
e
0