Maxim Integrated High-Speed Microcontroller Users Guide: DS80C390 Supplement - Manual (Page 22)

High-Speed Microcontroller User’s Guide: DS80C390 Supplement
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MD2, MD1, MD0
Bits 2-0 Stretch MOVX Select 2-0. These bits select the time by which external MOVX
cycles are to be stretched. This allows slower memory or peripherals to be
accessed without using ports or manual software intervention. The RD or WR
strobe will be stretched by the specified interval, which will be transparent to the
software except for the increased time to execute to MOVX instruction. All
internal MOVX instructions are performed at the 2 machine cycle rate.
MD2 MD1 MD0 Stretch Value MOVX Duration
0 0 0 0 2 Machine Cycles
0 0 1 1 3 Machine Cycles (reset default)
0 1 0 2 4 Machine Cycles
0 1 1 3 5 Machine Cycles
1 0 0 4 9 Machine Cycles
1 0 1 5 10 Machine Cycles
1 1 0 6 11 Machine Cycles
1 1 1 7 12 Machine Cycles
PORT 1 (P1)
7 6 5 4 3 2 1 0
SFR 90h P1.7
5 INT
P1.6
INT4
P1.7
3 INT
P1.4
INT2
P1.3
TXD1
P1.2
RXD1
P1.1
T2EX
P1.0
T2
RW-0 RW-0 RW-0 RW-0 RW-0 RW-0 RW-0 RW-1
R = Unrestricted Read, W = Unrestricted Write, -n = Value after Reset
P1.7–0
Bits 7–0 General-Purpose I/O Port 1. This register functions as the A0–A7 of the
nonmultiplexed address bus (when the MUX pin=1) or a general-purpose I/O
port (when the MUX pin=0). When serving as a general purpose I/O port all the
pins have an alternative function listed below. P1.2–7 contain functions that are
new to the 80C32 architecture. The Timer 2 functions on pins P1.1-0 are
available on the 80C32, but not the 80C31. Each of the functions is controlled by
several other SFRs. The associated Port 1 latch bit must contain a logic one
before the pin can be used in its alternate function capacity.
INT5
Bit 7
External Interrupt 5. A falling edge on this pin will cause an external interrupt 5
if enabled.
INT4
Bit 6 External Interrupt 4. A rising edge on this pin will cause an external interrupt 4
if enabled.
INT3
Bit 5
External Interrupt 3. A falling edge on this pin will cause an external interrupt 3
if enabled.
INT2
Bit 4 External Interrupt 2. A rising edge on this pin will cause an external interrupt 2
if enabled.
TXD1
Bit 3 Serial Port 1 Transmit. This pin transmits the serial port 1 data in serial port
modes 1, 2, 3 and emits the synchronizing clock in serial port mode 0.