COP87L89RB National Semiconductor, COP87L89RB Datasheet - Page 12

• Manufacturer Part Number: COP87L89RB
• Description: 8-Bit CMOS OTP Microcontrollers with 16k or 32k Memory/ CAN Interface/ 8-Bit A/D/ and USART
• Manufacturer: National Semiconductor

www.national.com
Oscillator Circuits
The chip can be driven by a clock input on the CKI input pin
which can be between DC and 10 MHz. The CKO output
clock is on pin G7. The CKI input frequency is divided by 10
to produce the instruction cycle clock (1/t
Figure 7 shows the Crystal diagram.
CRYSTAL OSCILLATOR
CKI and CKO can be connected to make a closed loop crys-
tal (or resonator) controlled oscillator.
Table 1 shows the component values required for various
standard crystal values.
Control Registers
CNTRL Register (Address X'00EE)
The Timer1 (T1) and MICROWIRE/PLUS control register
contains the following bits:
Bit 7
(k )
T1C3
TABLE 1. Crystal Oscillator Configuration, T
R1
T1C3
T1C2
T1C1
T1C0
MSEL
IEDG
SL1 & SL0
0
0
0
(M )
T1C2
R2
FIGURE 7. Crystal Oscillator Diagram
1
1
1
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)
(pF)
200
T1C1
C1
30
30
100–150
30–36
30–36
T1C0
(pF)
C2
DS100044-8
MSEL
CKI Freq.
(MHz)
0.455
10
4
IEDG
c
).
Conditions
V
V
V
SL1
A
CC
CC
CC
= 25˚C
= 5V
= 5V
= 5V
SL0
Bit 0
12
Reserved
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 This bit is reserved and should be zero
T2CNTRL Register (Address X'00C6)
The T2CNTRL control register contains the following bits:
Bit 7
Bit 7
T2C3
Bit 7
HC
HC
C
T1PNDA Timer T1 Interrupt Pending Flag (Autoreload
T1ENA
EXPND
BUSY
EXEN
GIE
LPEN
T0PND Timer T0 Interrupt pending
T0EN
µWPND MICROWIRE/PLUS interrupt pending
µWEN
T1PNDB Timer T1 Interrupt Pending Flag for T1B capture
T1ENB Timer T1 Interrupt Enable for T1B Input capture
T2C3
T2C2
T2C1
T2C0
T2PNDA
T2ENA
T2PNDB
T2ENB
C
T2C2
LPEN
T1PNDA
L Port Interrupt Enable (Multi-Input Wakeup/
Interrupt)
Timer T0 Interrupt Enable (Bit 12 toggle)
Enable MICROWIRE/PLUS interrupt
edge
edge
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)
Timer T2 mode control bit
Timer T2 mode control bit
Timer T2 mode control bit
Timer
modes 1 and 2, T2 Underflow Interrupt Pend-
ing Flag in timer mode 3
Timer T2 Interrupt Pending Flag (Autoreload
RA in mode 1, T2 Underflow in mode 2, T2A
capture edge in mode 3)
Timer T2 Interrupt Enable for Timer Underflow
or T2A Input capture edge
Timer T2 Interrupt Pending Flag for T2B cap-
ture edge
Timer T2 Interrupt Enable for Timer Underflow
or T2B Input capture edge
T2C1
T0PND
T2C0
T1ENA
T2
T0EN
T2PNDA
Start/Stop
EXPND
µWPND
T2ENA
µWEN
BUSY
control
T2PNDB
T1PNDB
EXEN
in
T2ENB
T1ENB
timer
Bit 0
GIE
Bit 0
Bit 0