EM78452 Datasheet, PDF (44/54 Pages) ELAN Microelectronics Corp – 8-Bit Microcontroller

EM78452
8-Bit Microcontroller
C1
OSCI
XTAL
OSCO
RS
C2
Fig. 5-18 Circuit for Crystal/Resonator
Table 10 Capacitor Selection Guide for Crystal Oscillator Ceramic Resonators
Oscillator Type Frequency Mode
Ceramic Resonator
HXT
Crystal Oscillator
HXT
Frequency
455 KHz
1.0 MHz
2.0 MHz
4.0 MHz
455 KHz
1.0 MHz
2.0 MHz
4.0 MHz
C1 (pF)
10~150
40~80
20~40
10~30
20~40
15~30
15
15
C2 (pF)
10~150
40~80
20~40
10~30
20~150
15~30
15
15
Fig. 5-19 Circuit for External R, Internal C Oscillator Mode
5.10 Code Option Register :
Word 0
Bit 5
ENWDT
Bit 4
CLKS
Bit 3
SPIHSK
Bit 2
REN
Bit 1
SDOS
Bit 0
WUTT
Bit 5 (ENWDT): Watchdog Timer enabled.
0: Enable
1: Disable
Bit 4 (CLKS): Clocks of each instruction cycle.
0: Two clocks
1: Four clocks
Bit 3 (SPIHSK): SPI handshake enable bit
0: enable SPI handshake function. When this bit is set to “0.” In SPI
Slave mode, after SPI control register bit 4(SSE) is set to “1” it will
send a high level through P91 (SRDY). Inform the “master” that the
“Slave” is ready.
1: disable SPI handshake function
40 •
Product Specification (V1.0) 10.18.2007
(This specification is subject to change without further notice)