RDC
®
RISC DSP Controller
R8810LV
RDC Semiconductor Co.
Rev:1.2
Subject to change without notice
27
Bus Hold
When the bus hold requested ( HOLD pin active high) by the another bus master, the microprocessor will issue a HLDA
in response to a HOLD request at the end of T4 or Ti. When the microprocessor is in hold status (HLDA is high), the AO15-
AO8, AD7-AD0, A19-A0, WR ,
RD
, DEN ,
1
S - 0
S , 6
S ,
BHE
, DT/
R
, and WB are floating, and the UCS , LCS ,
6
PCS -
5
PCS ,
3
MCS -
0
MCS and
3
PCS -
0
PCS will be drive high. After HOLD is detected as being low, the
microprocessor will lower the HLDA.
CLKOUTA
HOLD
HLDA
A19:A0
DEN
S6
S2:S0
AD7:AD0
RD
WR
DT/R
WLB
BUS HOLD ENTER WAVEFORM
2
7
Case 1
Case 2
Ti
T3
Ti
T4
Ti
Ti
Ti
Ti
Floating
Floating
Floating
Floating
Floating
Floating
Floating
Floating
Floating
Floating
AO15:AO8