cop8acc7 National Semiconductor Corporation, cop8acc7 Datasheet - Page 13

• Manufacturer Part Number: cop8acc7
• Description: 8-bit Cmos Otp Microcontroller With 16k Memory And High Resolution A/d
• Manufacturer: National Semiconductor Corporation

Oscillator Circuits
RC
Figure 7 shows the Crystal and R/C Oscillator diagrams.
CRYSTAL OSCILLATOR
CKI and CKO can be connected to make a closed loop
crystal (or resonator) controlled oscillator.
Table 1 shows the component values required for various
standard crystal values.
R/C OSCILLATOR
By selecting CKI as a single pin oscillator input, a single pin
R/C oscillator circuit can be connected to it. CKO is available
as a general purpose input, and/or HALT restart input.
Note: Use of the R/C oscillator option will result in higher electromagnetic
Table 2 shows the variation in the oscillator frequencies as
functions of the component (R and C) values.
(k )
TABLE 1. Crystal Oscillator Configuration, T
R1
0
0
0
>
FIGURE 7. Crystal and R/C Oscillator Diagrams
5 x POWER SUPPLY RISE TIME
emissions.
FIGURE 6. Recommended Reset Circuit
(M )
R2
1
1
1
(pF)
200
C1
30
30
100–150
30–36
30–36
(pF)
C2
DS012865-55
DS012865-54
(Continued)
CKI Freq
(MHz)
0.455
10
4
DS012865-53
Conditions
V
V
V
A
CC
CC
CC
= 25˚C
= 5V
= 5V
= 5V
13
Note 18: 3k
Note 19: 50 pF
Control Registers
CNTRL Register (Address X'00EE)
The Timer1 (T1) and MICROWIRE/PLUS control register
contains the following bits:
PSW Register (Address X'00EF)
The PSW register contains the following select bits:
The Half-Carry flag is also affected by all the instructions that
affect the Carry flag. The SC (Set Carry) and R/C (Reset
Carry) instructions will respectively set or clear both the carry
flags. In addition to the SC and R/C instructions, ADC,
SUBC, RRC and RLC instructions affect the Carry and Half
Carry flags.
ICNTRL Register (Address X'00E8)
The ICNTRL register contains the following bits:
Reserved
Bit 7
Bit 7
Bit 7
T1C3
(k )
HC
3.3
5.6
6.8
T1C3
T1C2
T1C1
T1C0
MSEL
IEDG
SL1 & SL0
HC
C
T1PNDA Timer T1 Interrupt Pending Flag (Autoreload
T1ENA
EXPND
BUSY
EXEN
GIE
Reserved This bit is reserved and should be zero.
R
TABLE 2. RC Oscillator Configuration, T
C
T1C2
(pF)
100
100
LPEN
82
C
T1PNDA
R
Half Carry Flag
Carry Flag
RA in mode 1, T1 Underflow in Mode 2, T1A
capture edge in mode 3)
Timer T1 Interrupt Enable for Timer Underflow
or T1A Input capture edge
External interrupt pending
MICROWIRE/PLUS busy shifting flag
Enable external interrupt
Global interrupt enable (enables interrupts)
C
200k
Timer T1 mode control bit
Timer T1 mode control bit
Timer T1 mode control bit
Timer T1 Start/Stop control in timer
modes 1 and 2, T1 Underflow Interrupt
Pending Flag in timer mode 3
Selects G5 and G4 as MICROWIRE/PLUS
signals SK and SO respectively
External interrupt edge polarity select
(0 = Rising edge, 1 = Falling edge)
Select the MICROWIRE/PLUS clock divide
by (00 = 2, 01 = 4, 1x = 8)
T0PND
T1C1
CKI Freq
2.2 to 2.7
1.1 to 1.3
0.9 to 1.1
200 pF
(MHz)
T1ENA
T0EN
T1C0
EXPND
µWPND
Instr. Cycle
MSEL
8.8 to 10.8
3.7 to 4.6
7.4 to 9.0
(µs)
µWEN
BUSY
IEDG
T1PNDB
A
EXEN
Conditions
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SL1
V
V
V
= 25˚C
CC
CC
CC
= 5V
= 5V
= 5V
T1ENB
Bit 0
GIE
Bit 0
SL0
Bit 0