Intel 87C196CA, Supplement To User’S Manual

Page: 117 / 136

A-9
SIGNAL DESCRIPTIONS
Table A-6. 83C196LD Default Signal Conditions
Port
Signals
Alternate
Functions
During RESET#
Active
Upon RESET#
Inactive
(Note 6) Idle
Power-
down
P0.7:2 — HiZ HiZ HiZ HiZ
P1.0 EPA0/T2CLK WK1 WK1 (Note 1) (Note 1)
P1.1 EPA1 WK1 WK1 (Note 1) (Note 1)
P1.2 EPA2/T2DIR WK1 WK1 (Note 1) (Note 1)
P1.3 EPA3 WK1 WK1 (Note 1) (Note 1)
P2.0 TXD WK1 WK1 (Note 1) (Note 1)
P2.1 RXD WK1 WK1 (Note 1) (Note 1)
P2.2 EXTINT WK1 WK1 (Note 1) (Note 1)
P2.4 — WK1 WK1 (Note 1) (Note 1)
P2.6 ONCE MD1 MD1 (Note 1) (Note 1)
P2.7 CLKOUT CLKOUT active,
LoZ0/1
CLKOUT active,
LoZ0/1
(Note 1) (Note 2)
P3.7:0 AD7:0 WK1 HiZ (Note 4) (Note 4)
P4.7:0 AD15:8 WK1 HiZ (Note 4) (Note 4)
P5.0 ALE/ADV# WK1 WK1 (Note 1) (Note 1)
P5.2 WR#/WRL# WK1 WK1 (Note 1) (Note 1)
P5.3 RD# WK1 WK1 (Note 1) (Note 1)
P6.0 EPA8 WK1 WK1 (Note 1) (Note 1)
P6.1 EPA9 WK1 WK1 (Note 1) (Note 1)
P6.4 SC0 WK1 WK1 (Note 1) (Note 1)
P6.5 SD0 WK1 WK1 (Note 1) (Note 1)
P6.6 SC1 WK1 WK1 (Note 1) (Note 1)
P6.7 SD1 WK1 WK1 (Note 1) (Note 1)
— EA# WK1 (Note 5) WK1 WK1 WK1
— RESET# LoZ0 MD1 MD1 MD1
— V
PP
HiZ HiZ LoZ1 LoZ1
— XTAL1
Osc input, HiZ Osc input, HiZ
Osc input,
HiZ
Osc input,
HiZ
— XTAL2 Osc output,
LoZ0/1
Osc output,
LoZ0/1
Osc output,
LoZ0/1
(Note 3)
NOTES:
1.
If P x_MODE.y = 0, port is as programmed.
If P
x_MODE.y = 1, pin is as specified by Px_DIR and the associated peripheral.
2. If P2_MODE.7 = 0, pin is as programmed. If P2_MODE.7 = 1, pin is LoZ0.
3. If XTAL1 = 0, pin is LoZ1. If XTAL1 = 1, pin is LoZ0.
4. If EA# = 0, port is HiZ. If EA# = 1, port is open-drain I/O.
5. Although EA# is weakly pulled high, do not allow it to float. Always tie EA# to V
CC
if it is not connected
to an external device.
6. The values in this column are valid until your software writes to P
x_MODE.