SM8958B
8-Bit Micro-controller
32KB Flash
& 1KB RAM embedded
Function Description
1. General Features
SM8958B is an 8-bit micro-controller. All of its functions and the detailed meanings of SFR will be given in the
following sections.
1.1 Embedded Flash
The program can be loaded into the embedded 32KB Flash memory via its writer.
1.2 IO Pads
The SM8958B has Five I/O ports: Port 0, Port 1, Port 2, Port 3, Port 4. Port 0~Port 3 are 8-bit ports. Port 4 is 4-bit
port. These are: quasi-bidirectional (standard 8051 port outputs) with Port 1~4, and open drain with Port 0.
All the pads are with slew rate to reduce EMI. The IO pads can withstand ESD in human body mode guaranteeing
the SM8958B’s quality in high electro-static environments.
1.3 System Control Register (SCONF)
Mnemonic: SCONF
Address: BFh
7
6
-
5
-
4
3
-
2
-
1
0
ALEI
Reset
02H
WDR
PDWUE
OME
WDR: Watch Dog Timer Reset.
When system reset by Watch Dog Timer overflow, WDR will be set to 1.
User should check WDR bit whenever un-predicted reset happened.
PDWUE: Power down wake-up enable bit.
Set 1 to enable wake-up from power-down state by external pin int0 or int1.
OME: On-chip 768B expanded RAM enable bit.
Set 1 to enable on-chip 768B expanded RAM access.
ALEI: ALE output inhibit bit.
When default, It can inhibit the clock signal in (Fosc/6) Hz output to the ALE pin.
When set to 1, the ALE pin output will stop to reduce EMI.
FOSVOS TEL: 021-58998693
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M085
Ver A SM8958B 3/7/2014
- 12 -