Kawasaki 80C51 Computer Hardware User Manual


 
KS152JB Universal Communications Controller
Technical Specifications
Kawasaki LSI USA, Inc. Page 7 of 120 Ver. 0.9 KS152JB2
between the RST pin being pulled low and the internal reset being generated. During this time the
CPU continues its normal operations.
The internal reset signal clears the SFRs except the port SFRs which have FFh written into them
and the Stack Pointer which has 07h written to it. The SBUF is however in an indeterminate state.
The Program Counter is reset to 0000h. The internal RAM is not affected by the reset and their
contents remain unchanged. On power up, their contents is indeterminate.
Table 3: Reset Values of the SFRs
SFR Name Reset Value SFR Name Reset Value
PC 0000H BRCL0-1 INDETERMINATE
ACC 00H BCRH0-1 INDETERMINATE
B 00H TL0 00H
PSW 00H TH0 00H
SP 07H TL1 00H
DPTR 0000H TH1 00H
P0-6 FFH ADR0-3 00H
RFIFO INDETERMINATE AMSK0-1 00H
RSTAT 00H BAUD 00H
SARH0-1 INDETERMINATE BKOFF INDETERMINATE
SARH0-1 INDETERMINATE SLOTTM 00H
S5 S6
S1 S2
S3 S4
S5 S6
S1 S2
S3 S4
S5 S6
S1 S2
S3 S4
ADDRINSTADDRINSTADDRINSTADDRINST
ADDRINSTADDR
RST
internal reset
ALE
PSEN
P0
Reset Timing