sx18ac ETC-unknow, sx18ac Datasheet - Page 12

• Manufacturer Part Number: sx18ac
• Description: Configurable Communications Controllers With Ee/flash Program Memory, In-system Programming Capability And On-chip Debug
• Manufacturer: ETC-unknow

SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75
4.3 OPTION Register
When the OPTIONX bit in the FUSE word is cleared, bits
7 and 6 of the OPTION register function as described
below.
When the OPTIONX bit is set, bits 7 and 6 of the
OPTION register read as ‘1’s.
© 2000 Scenix Semiconductor, Inc. All rights reserved.
RTW
RTE_IE
RTS
RTE_ES
PSA
PS2-PS0
Bit 7
RTW
RTE
_IE
RTCC/W register selection:
0 = Register 01h addresses W
1 = Register 01h addresses RTCC
RTCC edge interrupt enable:
0 = RTCC roll-over interrupt is enabled
1 = RTCC roll-over interrupt is disabled
RTCC increment select:
0 = RTCC increments on internal instruction
cycle
1 = RTCC increments upon transition on
RTCC pin
RTCC edge select:
0 = RTCC increments on low-to-high transi-
tions
1 = RTCC increments on high-to-low transi-
tions
Prescaler Assignment:
0 = Prescaler is assigned to RTCC, with di-
vide rate determined by PS0-PS2 bits
1 = Prescaler is assigned to WDT, and divide
rate on RTCC is 1:1
Prescaler divider (see Table 4-2)
RTS
RTE
_ES
PSA
PS2
PS1
Bit 0
PS0
- 12 -
Upon reset, all bits in the OPTION register are set to 1.
PS2, PS1, PS0
000
001
010
011
100
101
110
111
Table 4-2. Prescaler Divider Ratios
Divide Rate
RTCC
1:2
1:4
1:8
1:16
1:32
1:64
1:128
1:256
Watchdog Timer
Divide Rate
1:1
1:2
1:4
1:8
1:16
1:32
1:64
1:128
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