Typical application – Rainbow Electronics T89C5121 User Manual
Page 105
105
A/T8xC5121
4164G–SCR–07/06
Typical Application
Figure 54. Typical Application Diagram
Notes:
1. C4 and C5 must be placed near IC and have low ESR (<250m
Ω
)
2. Straight and short connections avoid any loop between:
- CVSS and V
SS
- C
V
CC
and C4, C5
3.
V
CC
connection of the master card must be placed as follows:
4. Current is limited to 10 mA.
5. CCLK should be routed far from CRST, CIO, CC4, CC8 and armored by ground plane.
10µF
V
CC
RxD
TxD
V
CC
TxD
RxD
XTAL1
XTAL2
LI
CPRES
CRST
CCLK
CC4
CC8
CIO
CV
CC
(1)(2)(3)
V
SS
I/O
C8
C4
CLK
(5)
RST
4.7 µF
V
SS
OE
RTS
V
SS
V
SS
INT1/OE
T0
V
SS
100nF
V
SS
DV
CC
EV
CC
100nF
V
SS
DV
CC
(4)
LED0
LED1
C1
C2
C3
C4
L1
4.7 µH
V
SS
V
SS
Y1
I/O
RST
CLK
Alternate
Card
CIO1
CRST1
CCLK1
V
CC
1Mohm
(optional resistor)
or V
CC
Serial Interface
CVSS
22 pF
V
SS
Vcc
Positive
Detection
Mode
Resonator
or Quartz with standard
capacitors
100nF
C5
C6
P1.2
P1.0
P1.1
P1.3
P1.4
P3.5
P3.7
P3.6
10 kohm
82 pF
V
SS
C7
CVCC
P3.6
P3.7
P3.4
P3.3
P3.1
P3.0
P1.5
c
V
CC
to card V
CC
CVSS
C4, C5