Z80189 Datasheet, PDF (100/107 Pages) Zilog, Inc. – GENERAL-PURPOSE EMBEDDED CONTROLLERS

Zilog
EMULATION MODES
PRELIMINARY
Z80189/Z8L189
GENERAL-PURPOSE EMBEDDED CONTROLLERS
Z80189 provides four modes of operation. The modes are
selected by the EV1 and EV2 pins. These four modes allow
for system development while the MIMIC is disabled, and
T is active.
OUT
Mode 0
Mode 1
Mode 2
Mode 3
EV2 EV1
0 0 Normal Mode, on-chip Z180
bus master
0 1 Emulation Adapter Mode
1 0 Emulator Probe Mode
1 1 Reserved Mode 0 Description
Mode 0 Normal Mode
This is the normal operating mode for the Z80189.
Mode 1 Description
The Emulation Adapter Mode enables system develop-
ment for the Z189 with a readily available Z180 emulator.
The Emulator provides the Z180 MPU and Z180 peripheral
functions to the target system, with their signals passing
through the emulation adapter. In Emulation Adapter Mode,
the Z189’s, Z180 MPU and Z180 peripheral signals are tri-
stated or physically disconnected. The Z189 continues to
provide its BRG, COM Port Decoder, MIMIC and Port
functions and signals to the target system. The Mode 1
effects on the Z189 are:
Signal
PHI
/M1
/MREQ,/MRD
/MWR
/IORQ
/RD
/WR
/RFSH
/HALT
ST
/BUSACK
/WAIT
A19,A18
A17-A0
D7-D0
TXA0
/RTS0
TXA1
/INT0
Mode 0
Normal
Mode 1
Emulation Adapter
Output
Output
Output
Output
Output
Output
Output
Output
Output
Output
Output
Input
Output
Output
Input/Output
Output
Output
Output
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Output
Input
Input
Input/Output
Tri-state
Tri-state
Tri-state
Output, Open-Drain
Mode 2 Description
In the Emulator Probe Mode, all the Z189 output signals are
tri-stated. This scheme allows a Z189 emulator probe to
grab onto the Z189 package leads on the target system.
Mode 3 Description
Reserved for Test Mode.
Note also that in Mode 1 and 3, the emulator must provide
/MREQ on the (/MREQ) Z80189 pin.
100
DS971890301