Z8673312PSG Datasheet, PDF (49/84 Pages) Zilog, Inc. – CMOS Z8 OTP Microcontrollers

CMOS Z8^® OTP Microcontrollers
Product Specification
45
Table 19. Port 3 Pin Assignments
Pin
I/O
CTC1 Analog Interrupt P0 HS P1 HS P2 HS Ext
P30
IN
IRQ3
P31
IN
P32
IN
T_IN
AN1
IRQ2
D/R
AN2
IRQ0
D/R
P33
IN
REF
IRQ1
D/R
P34
OUT
AN1-Out
R/D
DM
P35
OUT
R/D
P36
OUT
T_OUT
R/D
P37
OUT
An2-Out
Comparator Inputs. Port 3, P31, and P32, each have a comparator front end. The com-
parator reference voltage P33 is common to both comparators. In analog mode, P31 and
P32 are the positive input of the comparators and P33 is the reference voltage of the com-
parators.
Auto Latch. The Auto Latch puts valid CMOS levels on all CMOS inputs (except P33-
P31) that are not externally driven. Whether this level is 0 or 1, cannot be determined. A
valid CMOS level, rather than a floating node, reduces excessive supply current flow in
the input buffer. Auto Latches are available on Port 0, Port 1, Port 2, and P30. There are no
Auto Latches on P31, P32, and P33.
Low EMI Emission. The Z86E43/743/E44 can be programmed to operate in a low EMI
Emission Mode in the PCON register. The oscillator and all I/O ports can be programmed
as low EMI emission mode independently. Use of this feature results in:
• The pre-drivers slew rate reduced to 10 ns typical.
• Low EMI output drivers have resistance of 200 Ohms (typical).
• Low EMI Oscillator.
• Internal SCLK/TCLK= XTAL operation limited to a maximum of 4 MHz - 250 ns cycle
time, when Low EMI Oscillator is selected.
Note: ^{For emulation only:}
Do not set the emulator to emulate Port 1 in low EMI mode. Port 1
must always be configured in Standard Mode.
PS022901-0508
Electrical Characteristics