DS80CH11 Datasheet, PDF (31/88 Pages) Dallas Semiconductor – System Energy Manager

DS80CH11
WATCHDOG TIMER INTERRUPT / RESET TIMEOUT VALUES Table 5–1
WD1
0
0
1
1
WD0
0
1
0
1
INTERRUPT
TIME–OUT
2¹⁷ clocks
2²⁰ clocks
2²³ clocks
2²⁶ clocks
TIME (25 MHz)
5.243 ms
41.94 ms
335.54 ms
2684.35 ms
RESET
TIME–OUT
2¹⁷ + 512 clocks
2²⁰ + 512 clocks
2²³ + 512 clocks
2²⁶ + 512 clocks
TIME (25 MHz)
5.263 ms
41.96 ms
335.56 ms
2684.38 ms
5.4 PARALLEL I/O PORTS
The SEM incorporates the original four pseudo–bi–
directional parallel I/O ports found in the 80C52: Ports
0, 1, 2 and 3. All of these ports operate logically as docu-
mented in the Dallas High Speed Micro User’s Guide.
All of the Port 0, 1, 2, and 3 pins exhibit the same electri-
cal characteristics as documented in the user’s guide
except for P1.7 – P1.2 which are open–drain pins.
In addition to these basic ports, the SEM adds an addi-
tional seven 8–bit ports. All of these additional ports
incorporate the same logical I/O structure as the original
four, Ports 0 through 3. Therefore, they are pro-
grammed the same as Ports 0–3. The SFR addresses
for the new ports are as follows:
Port 4: 0A4H
Port 5: 0ACH
Port 6: 0BCH
Port 7: 0D4H
Port 8: 0E4H
Port 9: 0ECH
Port 10: 0F4H
5.4.1 Alternate Pin Function Summary
A number of port pins on the SEM offer an optional alter-
nate function. These functions are individually select-
able; i.e. each pin can be programmed for use as a gen-
eral purpose I/O or to serve the alternate function. In
order to use the alternate function, the associated port
latch must be programmed to a 1. The alternate func-
tions are summarized in Table 5–2 below.
PORT PIN ALTERNATE FUNCTIONS Table 5–2
PIN(S)
ALTERNATE
PIN(S)
ALTERNATE FUNCTION(S)
P0.7 – P0.0
AD7 – AD0
Mux. addr. / data bus
P1.7
–
None
P1.6
–
None
P1.5
SDA2
2–Wire Serial Port Data Input/Output 2
P1.4
SCL2
2–Wire Serial Port Clock 2
P1.3
SDA1
2–Wire serial port data Input / Output 1
P1.2
SCL1
2–Wire serial port clock 1
P1.1
T2EX
Timer 2 capture / reload input
P1.0
T2
Timer 2 output pulse
P2.7 – P2.0
A15 – A8
Address bus outputs
P3.7
RD
Read strobe output
P3.6
WR
Write strobe output
P3.5
T1
Timer 1 input
P3.4
T0
Timer 0 input
P3.3
INT1
External interrupt 1 input (active low)
P3.2
INT0
External interrupt 0 input (active low)
P3.1
TXD0
UART Transmit
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