Z8E001 Datasheet, PDF (37/49 Pages) Zilog, Inc. – CMOS OTP Microcontroller

Zilog
Z8E001
CMOS OTP Microcontroller
PORT B
Port B Description
Port B is a 5-bit, bidirectional, CMOS-compatible I/O port.
These five I/O lines can be configured under software con-
trol to be an input or output, independently. Input buffers
are Schmitt-triggered. See Figures 31 through 34 for dia-
grams of all five Port B pins.
In addition to standard input/output capability on all five
pins of Port B, each pin provides special functionality as
shown in the following table:
Table 6. Port B Special Functions
Port Pin
PB0
PB1
PB2
PB3
PB4
Input Special
Function
Stop Mode Recovery
Input
None
Interrupt1
Comparator
Reference Input
Comparator Signal
Input/Interrupt0/
Interrupt2
Output Special
Function
None
Timer0 Output
None
None
None
Special functionality is invoked via the Port B Special
Function Register. See Figure 30 for the arrangement and
control conventions for this register.
Register 0D7H
PTBSFR
D7
D6 D5 D4
D3 D2
D1 D0
1 = ENABLE PB0 AS SMR INPUT
0 = NO SPECIAL FUNCTIONALITY
1 = ENABLE PB1 AS TIMER0 OUTPUT
0 = NO SPECIAL FUNCTIONALITY
1 = ENABLE PB2 AS INT1 INPUT
0 = NO SPECIAL FUNCTIONALITY
1 = Analog Comparator on PB3 & PB4
0 = Digital Inputs on PB3 & PB4
1 = PB4 Interrupts Enabled
0 = PB4 Interrupts Disabled
RESERVED (MUST BE 0)
Figure 32. Port B Special Function Register
DS97Z8X1300
PRELIMINARY
37