The Z80185 and Z80195 are smart peripheral controller
devices designed for general data communications applications, and architected specifically to accommodate all
input and output (I/O) requirements for serial and parallel
connectivity. Combining a high-performance CPU core
with a variety of system and I/O resources, the Z80185/195
are useful in a broad range of applications. The Z80195 is
the ROMless version of the device.
The Z80185 and Z80195 feature an enhanced Z8S180
microprocessor linked with one enhanced channel of the
Z85230 ESCC™ serial communications controller, and 25
bits of parallel I/O, allowing software code compatibility
with existing software code.
■Enhanced Z8S180 MPU
■Four Z80 CTC Channels
■One Channel ESCC™ Controller
■Two 8-Bit Parallel I/O Ports
■Bidirectional Centronics Interface (IEEE 1284)
■Low-EMI Option
Seventeen lines can be configured as bidirectional
Centronics (IEEE 1284) controllers. When configured as a
1284 controller, an I/O line can operate in either the host or
peripheral role in compatible, nibble, byte or ECP mode. In
addition, the Z80185 includes 32 Kbytes of on-chip ROM.
These devices are well-suited for external modems using
a parallel interface, protocol translators, and cost-effective
WAN adapters. The Z80185/195 is ideal for handling all
laser printer I/O, as well as the main processor in costeffective printer applications.
Notes:
All Signals with a preceding front slash, "/", are active Low.
DS971850301
Power connections follow conventional descriptions below:
Voltage on all pins with respect to GND. Permanent LSI damage may
occur if maximum ratings are exceeded. Normal operation should be
recommended operating conditions. If these conditions are exceeded, it
could affect reliability of LSI.
The DC Characteristics and capacitance sections below
apply for the following standard test conditions, unless
otherwise noted. All voltages are referenced to GND (0V).
Positive current flows into the referenced pin (Test Load).
Operating Temperature Range:
S = 0°C to 70°C
Voltage Supply Range:
+4.5V ≤ VCC ≤ +5.5V
Stresses greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; operation of the device at
any condition above those indicated in the operational
sections of these specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods
may affect device reliability.
= 2 mA
I
OL
1.4 V
All AC parameters assume a load capacitance of 100 pF.
Add 10 ns delay for each 50 pF increase in load up to a
maximum of 150 pF for the data bus and 100 pF for
address and control lines. AC timing measurements are
referenced to 1.5 volts (except for clock, which is referenced to the 10% and 90% points). Maximum capacitive
load for PHI is 125 pF.
100 pF
= 250 µA
I
OH
Figure 3. Test Load Diagram
4
DS971850301
Zilog
PRELIMINARY
DC CHARACTERISTICS
VDD = 5.0V ±10%, VSS = 0V over specified temperature range, unless otherwise noted.
SymbolItemConditionMin.Typ.Max.Unit
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
V
IH
V
IL
V
OH
V
OL1
I
IL
Input “H” Voltage†V
Input “L” Voltage†V
Output “H” Voltage†V
Output “L” Voltage†V
Input LeakageVIN=0.5 to
Current All InputsVDD–0.51.0
Except XTAL,EXTALµA
I
TL
Tri-State LeakageVIN=0.5 to
CurrentVDD–0.51.0µA
VDD Supply Current*
Normal Operation
For 5.0V:f = 20 MHz60120mA
For 5.0V:f = 33 MHz68132mA
ICC*Power Dissipation*
System Stop Mode
For 5.0V:f = 20 MHz510mA
For 5.0V:f = 33 MHz713mA
Notes:
† See Class Reference Table
* V
min = VDD –1.0V, VIL max = 0.8V (All output terminals are at no load.)
IH
DS971850301
5
Zilog
TIMING DIAGRAMS
Z8S180 MPU Timing
PRELIMINARY
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
ø
Address
/WAIT
/MREQ
/IORQ
/RD
/WR
Opcode Fetch Cycle
I/O Write Cycle †
I/O Read Cycle †
T1T2TWT3T1T2TWT3T1
5
4
32
1
6
19
20
19
7
8
9b
9a
14
12
20
13
11
7
28b
11
28a
9
22
29
13
25
26 and 26a
11
11
/M1
ST
Data
IN
Data
OUT
/RESET
54
48
10
17
49
53
18
15
16
23
Figure 4. CPU Timing
(Opcode Fetch Cycle, Memory Read/Write Cycle
I/O Read/Write Cycle)
24
15
16
21
27
49
48
54
53
6
DS971850301
Zilog
TIMING DIAGRAMS (Continued)
Ø
32
31
/INTI
33
/NMI
/M1 [1]
/IORQ [1]
PRELIMINARY
30
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
16
15
/Data IN [1]
/MREQ [2]
/RFSH [2]
/BUSREQ
/BUSACK
Address
Data /MREQ,
/RD, /WR,
/IORQ
/HALT
39
3535
34
43
Notes:
[1] During /INT0 acknowledge cycle
[2] During refresh cycle
404142
34
3736
[3]
[3] Output buffer is off at this point
[4] Refer to Table C, parameter 7
3838
44
DS971850301
Figure 5. CPU Timing
(/INT0 Acknowledge Cycle, Refresh Cycle, BUS RELEASE mode
HALT mode, SLEEP mode, SYSTEM STOP mode)
7
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
Address
/IROQ
/RD
/WR
I/O Read Cycle
T1T2TWT3T1
0
28
9
29
13
Figure 6. CPU Timing
CPU or DMA Read/Write Cycle
I/O Write Cycle
T2TWT3
28
22
29
25
TOUT//DREQ
(At level
sense)
TOUT//DREQ
(At edge
sence)
ST
T1T2TwT3T1
Ø
45
[1]
46
45
[2]
45
[3]
17
18
[4]
DMA Control Signals
[1] tDRQS and tDRQH are specified for the rising edge of clock followed by T3.
[2] tDRQS and tDRQH are specified for the rising edge of clock.
[3] DMA cycle starts.
[4] CPU cycle starts.
Figure 7. DMA Control Signals
8
DS971850301
Zilog
TIMING DIAGRAMS (Continued)
Ø
TOUT/DREQ
SLP Instruction FetchNext Opcode Fetch
T3T1T2TSTST1T2
PRELIMINARY
Timer Data
Reg = 0000H
47
Figure 8. Timer Output Timing
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
Ø
/INTi
/NMI
A18-A0
/MREQ, /M1
/RD
/HALT
32
31
33
4344
DS971850301
Figure 9. SLEEP Execution Cycle
9
Zilog
CSI/O Clock
Transmit Data
(Internal Clock)
Transmit Data
(External Clock)
Receive Data
(Internal Clock)
PRELIMINARY
5757
5858
11 tcyc 11 tcyc
60596059
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
Receive Data
(External Clock)
11.5 tcyc
16.5 tcyc16.5 tcyc
62616162
11.5 tcyc
Figure 10. CSI/O Receive/Transmit Timing
10
DS971850301
Zilog
TIMING DIAGRAMS (Continued)
63
/MREQ
/RAMCS
/ROMCS
/IORQ
PRELIMINARY
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
64
/IOCS
Figure 11. /ROMCS and /RAMCS Timing
5152
EXTAL
VIL1
VIH1
VIH1
Figure 12. External Clock Rise Time
and Fall Time
VIL1
56
55
Figure 13. Input Rise and Fall Time
(Except EXTAL, /RESET)
DS971850301
11
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
AC CHARACTERISTICS
VDD = 5V ±10%, VSS = 0V, CL = 50 pF for outputs over
specified temperature range, unless otherwise noted.
7tASAddress Valid to (MREQ Falling or IORQ Falling)55ns
8tMED1PHI Falling to MREQ Falling Delay2515ns
9atRDD1PHI Falling to RD Falling Delay (IOC=1)2515ns
9btRDD1PHI Rising to RD Falling Delay (IOC=0)2515ns
10tM1D1PHI Rising to M1 Falling Delay3515ns
11tAHAddress Hold Time from (MREQ, IOREQ, RD, WR)55ns
12tMED2PHI Falling to MREQ Rising Delay2515ns
13tRDD2PHI Falling to RD Rising Delay2515ns
14tM1D2PHI Rising to M1 Rising Delay4015ns
15tDRSData Read Setup Time105ns
16tDRHData Read Hold Time00ns
17tSTD1PHI Falling to ST Falling Delay3015ns
18tSTD2PHI Falling to ST Rising Delay3015ns
19tWSWAIT Setup Time to PHI Falling1510ns
20tWHWAIT Hold Time from PHI Falling105ns
21tWDZPHI Rising to Data Float Display3520ns
22tWRD1PHI Rising to WR Falling Delay2515ns
23tWDDPHI Rising to Write Data Delay Time2515ns
24tWDSWrite Data Setup Time to WR Falling1010ns
25tWRD2PHI Falling to WR Rising Delay2515ns
26tWRPWrite Pulse Width (Memory Write Cycle)7545ns
Specifications 1 through 5 refer to an external clock input on EXTAL, and
provisionally to PHI clock output. When a quartz crystal is used with the
on-chip oscillator, a lower maximum frequency than that implied by spec.
#1 may apply.
12
DS971850301
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
AC CHARACTERISTICS (Continued)
Z80185 / Z80195Z80185 / Z80195
(20 MHz)(33 MHz)
No.Symbol ParameterMinMaxMinMaxUnits
28a tIODPHI Falling to IORQ Falling Delay IOC = 1)2515ns
28b tIODPHI Rising to IORQ Fallin g Delay (IOC =0)2515ns
29tIOD2PHI Falling to IORQ Rising Delay2515ns
30tIOD3M1 Falling to IORQ Falling Delay10080ns
31tINTSINT Setup Time to PHI Falling2015ns
32tINTHINT Hold Time from PHI Falling1010ns
33tNMIWNMI Pulse Width3525ns
34tBRSBUSREQ Setup Time to PHI Falling1010ns
35tBRHBUSREQ Hold Time from PHI Falling1010ns
36tBAD1PHI Rising to BUSACK Falling Delay2515ns
37tBAD2PHI Falling to BUSACK Rising Delay2515ns
38tBZDPHI Rising to Bus Floating Delay Time4030ns
39tMEWHMREQ Pulse Width (High)tcy –15tcy –10ns
40tMEWLMREQ Pulse Width (Low)2tcy –152tcy–10ns
41tRFD1PHI Rising to RFSH Falling Delay2015ns
42tRFD2PHI Rising to RFSH Rising Delay2015ns
43tHAD1PHI Rising to HALT Falling Delay1515ns
44tHAD2PHI Rising to HALT Rising Delay1515ns
45tDRQSDREQ Setup Time to PHI Rising2015ns
46tDRQHDREQ Hold Time from PHI Rising2015ns
47tTODPHI Falling to Timer Output Delay7550ns
48tRESRESET Setup Time to PHI Falling4025ns
49tREHRESET Hold Time From PHI Falling2515ns
50tOSCOscillator Stabilization Time2020ms
51tEXrExternal Clock Rise Time (EXTAL)105ns
52tEXfExternal Clock Fall Time (EXTAL)105ns
53tRrReset Rise Time5050ms
54tRfReset Fall Time5050ms
55tIrInput Rise Time (Except EXTAL, RESET)5050ns
56tIfInput Fall Time (Except EXTAL, RESET)5050ns
57tSTDICSIO Transmit Data Delay Time7560ns
(Internal Clock Operation)
58tSTDECSIO Transmit Data Delay Time7.5 tcy +757.5 tcy +60ns
(External Clock Operation)
59tSRSICSIO Receive Data Setup Time7560ns
(Internal Clock Operation)
60tSRHICSIO Receive Data Hold Time7560ns
(Internal Clock Operation)
61tSRSECSIO Receive Data Setup Time7560ns
(External Clock Operation)
62tSRHECSIO Receive Data Hold Time7560ns
(External Clock Operation)
63tdCSMREQ Valid to RAMCS and ROMCS Valid Delay1515ns
64tdIOCSRising IORQ Valid to Rising IOCS Valid Delay1010ns
DS971850301
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Zilog
PRELIMINARY
AC CHARACTERISTICS (Continued)
Read/Write External Bus Master Timing
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
Address
/IORQ
/RD
Data
/WR
Data
A7-A0
B7
B8
B1
B9
B2
B2
B6
B4
B5
Data Out
B3
Data In
Figure 14. Read/Write External Bus Master Timing
14
DS971850301
Zilog
PRELIMINARY
AC CHARACTERISTICS (Continued)
General-Purpose I/O Timing Port Timing
Parameters referenced in Figure 15 appear in the following
Tables. Note: Port 2 timing is different, even when Bidirectional Centronics feature is not in active use.
I/O Port Timing
(Output)
T1
T2
0
TWT3
T1T2
TW
T3T1T2
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
TW
T3
A0-A7
Port Data Dir. Reg. Addr. (Input)Port Data Reg. Addr. (Input)Port Data Reg. Addr. (Input)
B7
/IORQ
D0-D7
/WR
B2
Port
I/O Port Timing (Input)
A0-A7
/IORQ
(In) 'OO'H (Change Port To
Port Data Dir. Reg.
Output)
B6
Addr. (Input)
B7
Port Output Data 1
(In)
B3
B2
B6
B3
Port (Output)
A1
Port Data Reg.
Addr. (Input)
A1A2
B7
Port Output Data 2 (In)
B6
B2
Port Output Data 1 (Out)
Port Data Reg.
D0-D7
/WR
/RD
Port
DS971850301
Previous
Output
(In) 'FF'H (Change
Port To Input)
Port Data 1 (Out)
B2
B4
Port Input Data
1 (In)
Figure 15. PORT Timing
Port Data
B2
B4
Port Input Data
2 (In)
2 Out
15
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
I/O Port Timing
Z80185 / Z80195Z80185 / Z80195
(20 MHz)(33 MHz)
No.SymbolParameterMinMaxMinMaxUnits
A1TdWR (PIA)Data Valid Delay from WR Rise6060ns
External Bus Master Timing
Z80185 / Z80195Z80185 / Z80195
(20 MHz)(33 MHz)
No.SymbolParameterMinMaxMinMaxUnits
B1TsA(wf)Address Valid to WR or
(rf)RD Fall Time4040ns
B2TsIO(wf)IORQ Fall to WR or
(rf)RD Fall Time2020ns
B3ThData Hold Time (from WR Rise)55ns
B4TdRD(DO)RD Fall to Data Out Delay3535ns
B5TdRIr(DOz)RD,IORQ Rise to Data Float Time55ns
B6TsDI(WRf)Data In to WR Fall Setup Time2020ns
B7TsA(IORQf)Address to IORQ Fall Setup Time2020ns
B8TsA(RDf)Address to RD Fall Setup Time4040ns
B9TsA(WRf)Address to WR Fall Setup Time4040ns
16
DS971850301
Zilog
AC CHARACTERISTICS (Continued)
EMSCC Timing
Ø
/WR
/RD
Wait
PRELIMINARY
1
2
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
/INT
EMSCC Timing Parameters
No.SymbolParameterMinMaxUnit
1TdWR(W)/WR Fall to Wait Valid Delay50ns
2TdRD(W)/RD Fall to Wait Valid Delay50
6TdPC(INT)Clock to /INT Valid Delay160
6
Figure 16. EMSCC AC Parameters
20 MHz
DS971850301
17
Zilog
EMSCC General Timing Diagram
PCLK
Wait
3
/RTxC, /TRxC
Receive
4567
RxD
10
/TRxC, /RTxC
Transmit
TxD
PRELIMINARY
2
1112
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
/TRxC
Output
/RTxC
/TRxC
/CTS, /DCD
13
1415
16
17
1819
20
2121
Figure 17. EMSCC General Timing Diagram
18
DS971850301
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLES
AC CHARACTERISTICS (Continued)
EMSCC General Timing
20 MHz
No.SymbolParameterMinMaxNotes
2TdPC(W)/PCLK to Wait Inactive170
3TsRxC(PC)/RxC to /PCLK Setup Time NA[1,4]
4TsRxD(RxCr)RxD to /RxC Setup Time0[1]
5ThRxD(RxCr)RxD to /RxC Hold Time 45[1]
6TsRxD(RxCf)RxD to /RxC Setup Time 0[1,5]
7ThRxD(RxCf)RxD to /RxC Hold Time 45[1,5]
10TsTxC(PC)/TxC to /PCLK Setup Time NA[2,4]
11TdTxCf(TXD)/TxC to TxD Delay70[2]
12TdTxCr(TXD)/TxC to TxD Delay70[2,5]
13TdTxD(TRX)TxD to TRxC Delay 8070
14TwRTxhRTxC High Width 70[6]
15TwRTxITRxC Low Width 70[6]
16aTcRTxRTxC Cycle Time 200[6,7]
16bTxRx(DPLL)DPLL Cycle Time Min 50[7,8]
17TcRTxxCrystal OSC. Period 611000[3]
18TwTRxhTRxC High Width70[6]
Z80185/Z80195
19TwTRxlTRxC Low Width70[6]
20TcTRxTRxC Cycle Time 200[6,7]
21TwExTDCD or CTS Pulse Width 60
Notes:
[1] RxC is /RTxC or /TRxC, whichever is supplying the receive clock.
[2] TxC is /TRxC or /RTxC, whichever is supplying the transmit clock.
[3] Both /RTxC and /SYNC have 30 pF capacitors to Ground connected to them.
[4] Synchronization of RxC to PCLK is eliminated in divide-by-four operation.
[5] Parameter applies only to FM encoding/decoding.
[6] Parameter applies only for transmitter and receiver; DPLL and baud
rate generator timing requirements are identical to case PCLK requirements.
[7] The maximum receive or transmit data rate is 1/4 PCLK.
[8] Applies to DPLL clock source only. Maximum data rate of 1/4 PCLK
still applies. DPLL clock should have a 50% duty cycle.
These AC parameter values are preliminary and subject to change without notice.
DS971850301
19
Zilog
EMSCC System Timing Diagram
/RTxC, /TRxC
Receive
/W/REQ
Wait
/INT
/RTxC, /TRxC
Transmit
PRELIMINARY
2
4
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
Wait
/INT
/CTS,
/DCD
/INT
6
8
10
Figure 18. EMSCC System Timing
20
DS971850301
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLES
AC CHARACTERISTICS (Continued)
EMSCC System Timing
20 MHz
No.SymbolParameterMinMaxNotes
2TdRxC(W)/RxC to /Wait Inactive1318[1,2]
4TdRxC(INT)/RxC to /INT Valid1522[1,2]
6TdTxC(W)/TxC to /Wait Inactive817[1,3]
8TdTxC(INT)/TxC to /INT Valid917[1,3]
10TdExT(INT)/DCD or /CTS to /INT Valid39[1]
Notes:
[1] Open-drain output, measured with open-drain test load.
[2] /RxC is /RTxC or /TRxC, whichever is supplying the receive clock.
Valid ESCC
Addr * IORQ
[3] /TxC is /TRxC or /RTxC, whichever is supplying the transmit clock.
[4] Units equal to TcPc
These AC parameter values are preliminary and subject to change
without notice.
Z80185/Z80195
1
/RD or
/WR
Figure 19. EMSCC External Bus Master Timing
External Bus Master Interface Timing (SCC Related Timing)
Z80185 / Z80195Z80185 / Z80195
(20 MHz)(33 MHz)
NoSymbolParameterMinMaxMinMaxUnitNotes
1TrCValid Access Recovery Time4TcC4TcCns[1]
Notes:
[1] Applies only between transactions involving the EMSCC.
These AC parameter values are preliminary and subject to change
without notice.
TCC = EMSCC Clock Period Time
A0-A19.
A0-A19 is a 20-bit address bus that provides the address
for memory data bus cycles up to 1 Mbyte, and I/O data
bus cycles up to 64 Kbytes. The address bus enters a High
impedance state during reset and external bus acknowledge cycles. This bus is an input when /BUSACK is Low.
No address lines are multiplexed with any other signals.
D0-D7.
D7 constitute an 8-bit bidirectional data bus, used to
transfer information to and from I/O and memory devices.
The data bus enters the High impedance state during reset
and external bus acknowledge cycles, as well as during
SLEEP and HALT states.
/RD.
cates that the CPU is ready to read data from memory or
an I/O device. The addressed I/O or memory device
should use this signal to gate data onto the CPU data bus.
This pin is tri-stated during bus acknowledge cycles.
/WR.
cates that the CPU data bus holds valid data to be stored
at the addressed I/O or memory location. This pin is tristated during bus acknowledge cycles.
/IORQ.
/IORQ indicates that the address bus contains a valid I/O
address for an I/O read or I/O write operation. /IORQ is also
generated, along with /M1, during the acknowledgment of
the /INT0 input signal to indicate that an interrupt response
vector can be placed onto the data bus. This pin is tristated during bus acknowledge cycles.
/M1.
with /MREQ, /M1 indicates that the current cycle is the
opcode fetch cycle of an instruction execution. Together
with /IORQ, /M1 indicates that the current cycle is for an
interrupt acknowledge. It is also used with the /HALT and
ST signal to indicate the status of the CPU machine cycle.
The processor can be configured so that this signal is
compatible with the /M1 signal of the Z80, or with the /LIR
signal of the Z64180. This pin is tri-stated during bus
acknowledge cycles.
/MREQ.
state). /MREQ indicates that the address bus holds a valid
address for a memory read or memory write operation. It is
included in the /RAMCS and /ROMCS signals, and because of this may not be needed in some applications. This
pin is tri-stated during bus acknowledge cycles.
Address Bus
Data Bus
Read
(input/output, active Low, tri-state). /RD indi-
Write
(input/output, active Low, tri-state). /WR indi-
I/O Request
Machine Cycle 1
Memory Request
(input/output, active High, tri-state).
(bidirectional, active High, tri-state). D0-
(input/output, active Low, tri-state).
(input/output, active Low). Together
(input/output, active Low, tri-
/WAIT. (input/open-drain output, active Low.) /WAIT indicates to the MPU that the addressed memory or I/O
devices are not ready for a data transfer. This input is used
to induce additional clock cycles into the current machine
cycle. External devices should also drive this pin in an
open-drain fashion. This results in a “wired OR” of the Wait
indications produced by external devices and those produced by the two separate Wait State generators in the
Z80185. If the wire-ORed input is sampled Low, then
additional wait states are inserted until the /WAIT input is
sampled High, at which time the cycle is completed.
/HALT.
is asserted after the CPU has executed either the HALT or
SLP instruction, and is waiting for either non-maskable or
maskable interrupt before operation can resume. It is also
used with the /M1 and /ST signals to indicate the status of
the CPU machine cycle. On exit of Halt/Sleep, the first
instruction fetch is delayed 16 clock cycles after the /HALT
pin goes High.
/BUSACK.
/BUSACK indicates to the requesting device that the MPU
address and data bus, as well as some control signals,
have entered their High impedance state.
/BUSREQ.
used by external devices (such as DMA controllers) to
request access to the system bus. This request has a
higher priority than /NMI and is always recognized at the
end of the current machine cycle. This signal stops the
CPU from executing further instructions and places the
address and data buses, and other control signals, into the
High impedance state.
/NMI.
gered). /NMI has a higher priority than /INT and is always
recognized at the end of an instruction, regardless of the
state of the interrupt enable flip-flops. This signal forces
CPU execution to continue at location 0066H.
/INT0.
output, active Low). This signal is generated by internal
and external I/O devices. External devices should also
drive this signal in an open-drain fashion. The CPU will
honor this request at the end of the current instruction cycle
as long as it is enabled, and the /NMI and /BUSREQ signals
are inactive. The CPU acknowledges this interrupt request
with an interrupt acknowledge cycle. During this cycle,
both the /M1 and /IORQ signals will become active.
Halt/Sleep Status
Bus Acknowledge
Bus Request
Non-Maskable Interrupt
(output, active Low). This output
(output, active Low).
(input, active Low). This input is
(input, negative edge trig-
Maskable Interrupt Request 0
(input/open-drain
DS971850301
23
Zilog
PRELIMINARY
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
/INT1, /INT2.
active Low). These signals are generated by external I/O
devices. The CPU will honor these requests at the end of
the current instruction cycle as long as the /NMI, /BUSREQ,
and /INT0 signals are inactive. The CPU will acknowledge
these interrupt requests with an interrupt acknowledge
cycle. Unlike the acknowledgment for /INT0 during this
cycle, neither the /M1 nor the /IORQ signals will become
active. These pins may be programmed to provide active
Low level, rising or falling edge interrupts. The level of the
external /INT1 and /INT2 pins may be read in the Interrupt
Edge Register.
/RFSH.
/MREQ active indicate that the current CPU machine cycle
and the contents of the address bus should be used for
refresh of dynamic memories. The low order eight bits of
the address bus (A7-A0) contain the refresh address.
Maskable Interrupt Requests 1 and 2
Refresh
(output, active Low, tri-state). /RFSH and
inputs,
Z80185 UART and CSIO Signals
CKA0/CKS.
output). An optional clock input or output for ASCI channel
0 or the Clocked Serial I/O Port.
/DCD0/CKA1.
Clock 1
for ASCI channel 0, or a clock input or output for ASCI
channel 1.
/RTS0/TxS.
Data
(output). A programmable modem control output for
ASCI channel 0, or the serial output from the CSIO channel.
/CTS0/RxS.
Data
(input). A Low-active modem control input for ASCI
channel 0, or the serial data input to the CSIO channel.
TXA0.
from ASCI channel 0.
RXA0.
ASCI channel 0.
RXA1.
ASCI channel 1.
Asynchronous Clock 0 or Serial Clock
(input/
Data Carrier Detect 0 or Asynchronous
(input/output). A Low-active modem status input
Request to Send 0 or Clocked Serial Transmit
Clear to Send 0 or Clocked Serial Receive
Transmit Data 0
Receive Data 0
Receive Data 1
(output). This output transmits data
(input). This input receives data for
(input). This input receives data for
Multiplexed Signal
TOUT//DREQ.
or output). This pin can be programmed to be either TOUT,
the High-active pulse output from PRT channel 1, or a Lowactive DMA Request input from an external peripheral.
Timer Out or External DMA Request
(input
Z80185 EMSCC Signals
TXD.
Transmit Data
data at standard TTL levels.
RXD.
Receive Data
at standard TTL levels.
/TRXC.
functions under program control. /TRXC may supply the
receive clock or the transmit clock in the input mode or
supply the output of the digital phase-locked loop, the
crystal oscillator, the baud rate generator, or the transmit
clock in the output mode.
/RTXC.
under program control. /RTXC may supply the receive
clock, the transmit clock, the clock for the baud rate
generator, or the clock for the digital phase-locked loop.
The receive clock may be 1, 16, 32, or 64 times the data
rate in asynchronous mode.
/CTS.
programmed as an “auto enable”, a Low on it enables the
EMSCC transmitter. If not programmed as an auto enable,
it can be used as a general-purpose input. This pin is
Schmitt-trigger buffered to accommodate slow rise-times.
The EMSCC detects transitions on this input and can
interrupt the processor on either logic level transition.
/DCD.
functions as an EMSCC receiver enable when programmed
as an “auto enable”; otherwise it can be used as a generalpurpose input pin. The pin is Schmitt-trigger buffered to
accommodate slow rise-times. The EMSCC detects transitions on this pin and can interrupt the processor on either
logic level transition.
Transmit/Receive Clock
Receive/Transmit Clock
Clear To Send
Data Carrier Detect
(output). This output transmits serial
(input). This input receives serial data
(input or output). This pin
(input). This pin functions
(input, active Low). If this pin is
(input, active Low). This pin
TXA1.
Transmit Data 1
from ASCI Channel 1.
24
(output). This output transmits data
DS971850301
Zilog
PIN DESCRIPTIONS (Continued)
PRELIMINARY
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
EMSCC Signals
/RTS.
Request to Send
Request to Send (RTS) bit in Write Register 5 is set, the
/RTS signal goes Low. When the RTS bit is reset in the
Asynchronous mode and auto enables is on, the signal
goes High after the transmitter is empty. In Synchronous
mode, or in Asynchronous mode with auto enables off, the
/RTS pin strictly follows the state of the RTS bit. Thus the pin
can be used as a general-purpose output. In a special
“AppleTalk” mode on the Z80185, the pin is under hardware control.
/DTR.
Data Terminal Ready
“/DTR//REQ” functionality found in other SCC family members has been reconfigured internal to the EMSCC
megacell. The /DTR output is routed to this pin, while the
/REQ signal is routed to the DMA request multiplexing
logic as described in a later section on the EMSCC. This
pin follows the state of the DTR bit in WR5 of the EMSCC.
Note: The /W/REQ pin present on other SCC family members has its two possible functions reconfigured internal to
the EMSCC, and both functions are handled internally to
the Z80185. The Wait output of the EMSCC drives the
/WAIT signal in a wire-ORed fashion with other internal and
external peripherals. The /REQ component is routed to the
DMA request multiplexing logic as described in a later
section on the EMSCC.
(output, active Low). When the
(outputs, active Low). The
Z80185 Parallel Ports
PIA16-14.
These lines can be configured as inputs or outputs, or as
the “zero count/timeout” outputs of three of the four CTC
channels, on a bit-by-bit basis.
Port 1, Bits 6-4 or CTC ZC/TO2-0
(input/output).
PIA13-10.
output). These lines can be configured as inputs or outputs, or as the “clock/trigger” inputs of the four CTC
channels, on a bit-by-bit basis.
PIA27-20.
These lines can be configured as inputs or outputs on a bitby-bit basis when not used for Bidirectional Centronics
operation. However, when used for Bidirectional Centronics
operation, software and hardware controls the direction of
all eight as a unit.
Port 1, Bits 3-0 or CTC CLK/TRG3-0
Port 2, Data, or Bidirectional
(input/output).
(input/
Bidirectional Centronics Pins
nStrobe, nAutoFd, nSelectIn, nInit (input/outputs). These
are inputs when using P27-20 for the Peripheral side of a
Centronics controller, or outputs when using P27-20 for the
Host side of such an interface. In certain P1284 modes,
these pins assume other names as described in the
section on the Centronics P1284 controller. When not
using P27-20 for a Centronics controller, these pins can be
used as general-purpose inputs or outputs.
Busy, nAck, PError, nFault, Select (input/outputs). These
are outputs when using P27-20 for the Peripheral side of a
Centronics P1284 controller, or inputs when using P27-20
for the Host side of such an interface. In certain P1284
modes, these pins have other names as described in the
section on the Centronics P1284 controller. When not
using P27-20 for a Centronics P1284 controller, these pins
can be used as general-purpose outputs or inputs. These
pins always function in the opposite direction of the preceding group.
DS971850301
25
Zilog
PRELIMINARY
System Control Signals
ST.
Status
/M1 and /HALT output to indicate the nature of each CPU
machine cycle.
/RESET.
used for initializing the Z80185 and other devices in the
system. It must be kept Low for at least three system clock
cycles.
IEI.
Interrupt Enable Signal
with IEO to form a priority daisy-chain when there are
external interrupt-driven Z80-compatible peripherals.
IEO.
In an interrupt daisy-chain, IEO controls the interrupt of
external peripherals. IEO is active when IEI is 1 and the
CPU is not servicing an interrupt from the on-chip peripherals.
/IOCS. /IOCS decodes /IORQ, /M1, and as many address
lines as are necessary to ensure it is activated for an I/O
space access to any register in any block of eight registers
that does not contain any on-chip registers. Also included
in the decode is any programmed relocation of the “180
register set” in the ICR, and the “Decode High I/O” bit in the
System Configuration Register. If the “180 registers” aren’t
relocated, and “Decode High I/O” is 0, /IOCS is active from
address XX40 though XXD7, XXF8 through XXFF, and
NN00 through NN3F, where NN are non-zero. If the “180
registers” are not relocated and “Decode High I/O” is 1,
/IOCS is active from 0040 through 00D7, and 00F8 through
FFFF. /IOCS is active when an external master is in control
of the bus, as well as when the Z80185 processor has
control.
(output, active High). This signal is used with the
Reset Signal
Interrupt Enable Output Signal
(input, active Low). /RESET signal is
(input, active High). IEI is used
(output, active High).
SMART PERIPHERAL CONTROLLERS
/RAMCS.
signal is driven Low for memory accesses at addresses
that fall between the values programmed into the RAMLBR
and RAMUBR registers. It is active when an external
master has control of the bus, as well as when the Z80185
processor is in control.
/ROMCS.
output is driven Low for memory accesses between the top
of on-chip ROM (if on-chip ROM is enabled) and the value
programmed into the ROMBR register. It is active when an
external master has control of the bus, as well as when the
Z80185 processor is in control.
XTAL.
Crystal oscillator connection and should be left open if an
external clock is used instead of a crystal. The oscillator
input is not a TTL level (reference DC Characteristics
section).
EXTAL.
pin functions as a Crystal oscillator connection. An external clock can be input to the Z80185 on this pin when a
crystal is not used. This input is Schmitt-triggered.
PHI.
processor’s reference clock, and is provided for the use of
external logic. The frequency of this output may be equal
to, or one-half that of the crystal or input clock frequency,
depending on an internal register bit.
RAM Chip Select
ROM Chip Select
Crystal
(input, active High). This pin functions as the
External Clock/Crystal
System Clock
(output, active High). This output is the
(output, active Low). This
(output, active Low). This
(input, active High). This
Z80185/Z80195
26
DS971850301
Zilog
PRELIMINARY
Z80185 MPU FUNCTIONAL DESCRIPTION
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
The Z80185 includes a Zilog Z8S180 MPU (Static Z80180
MPU). This allows software code compatibility with existing Z80/Z180 software code. The following is an overview
of the major functional units of the Z80185.
The MPU portion of the Z80185 is the Z8S180 core with
added features and modifications. The single-channel
EMSCC of the Z80185 is compatible with the Z85233
EMSCC and features additional enhancements for
LocalTalk and the demultiplexing of the /DTR//REQ and
/WT//REQ lines.
Architecture
The Z80185 combines a high performance CPU core with
a variety of system and I/O resources useful in a broad
range of applications. The CPU core consists of four
functional blocks:
■Clock Generator
■Bus State Controller (Dynamic Memory Refresh)
■Memory Management Unit (MMU)
■Central Processing Unit (CPU).
The integrated I/O resources make up the remaining
functional blocks:
■Direct Memory Access (DMA control—two channels)
■Asynchronous Serial Communications Controller
(ASCI, two channels)
■Programmable Reload Timers (PRT, two channels)
■Clocked Serial I/O
■Channel (CSIO)
■Enhanced Z85C30 (EMSCC)
■Counter/Timer Channels (CTC)
■Parallel I/O
■Bidirectional Centronics Controller.
Clock Generator. This logic generates the system clock
from either an external crystal or clock input. The external
clock is divided by two, or one if programmed, and is
provided to both internal and external devices.
Bus State Controller. This logic performs all of the status
and bus control activity associated with both the CPU and
some on-chip peripherals. This includes wait state timing,
reset cycles, DRAM refresh, and DMA bus exchanges.
Interrupt Controller. This logic monitors and prioritizes
the variety of internal and external interrupts and traps to
provide the correct responses from the CPU. To maintain
compatibility with the Z80 CPU, three different interrupt
modes are supported.
Memory Management Unit. The MMU allows the user to
“map” the memory used by the CPU (logically only 64
Kbytes) into the 1 Mbyte addressing range supported by
the Z80185. The organization of the MMU object code
maintains compatibility with the Z80 CPU while offering
access to an extended memory space. This is accomplished by using an effective “common area-banked area”
scheme.
Central Processing Unit. The CPU is microcoded to
provide a core that is object-code compatible with the Z80
CPU. It also provides a superset of the Z80 instruction set,
including 8-bit multiply. This core has been modified to
allow many of the instructions to execute in fewer clock
cycles.
DMA Controller. The DMA controller provides high-speed
transfers between memory and I/O devices. Transfer operations supported are memory-to-memory, memory to or
from I/O, and I/O-to-I/O. Transfer modes supported are
request, burst, and cycle steal. DMA transfers can access
the full 1 Mbyte addressing range with a block length up to
64 Kbytes, and can cross over the 64 Kbytes boundaries.
DS971850301
27
Zilog
XTAL
EXTAL
PRELIMINARY
/WR
/RD
/RESET
/M1
/MREQ
/HALT
/IORQ
/BUSREQ
/WAIT
/RFSH
/BUSACK
SMART PERIPHERAL CONTROLLERS
Z80185/Z80195
/NMI
/INT0
/INT1
/INT2
TOUT/
/DREQ
/RTS0/TxS
/CTS0/RxS
CKA0/CKS
Timing &
Ø
Clock
Generator
16-Bit
Programmable
Reload Timers
(2)
Clocked
Serial I/O
Port
Address Bus (16-Bit)
MMU
Bus State Control
CPU
DMACs
(2)
Asynchronous
SCI
(Channel 0)
Data Bus (8-Bit)
Asynchronous
SCI
(Channel 1)
Interrupt
TOUT//DREQ
TxA0
CKA0/CKS
RxA0
/RTS0
/CTS0
/DCD0
TxA1
DCD0/CKA1
RxA1
28
A19-A0D7-D0
Figure 21. Z8S180 MPU Block Diagram
DS971850301
Zilog
PRELIMINARY
Z80185 MPU FUNCTIONAL DESCRIPTION (Continued)
DMA Controller
SMART PERIPHERAL CONTROLLES
Z80185/Z80195
The two DMA channels of the Z80185 can transfer data to
or from the EMSCC channel, the parallel interface, the
async ports, or an external device. The I/O device encoding in SAR18-16 and DAR18-16 of the existing Z80180 is
modified as shown in Table 1.
Table 1. SAR18-16 and DAR18-16 I/O Device Encoding
SM1-0SAR18-16Source
11000ext (TOUT/DREQ)
11001ASCI0 Rx
11010ASCI1 Rx
11011EMSCC Rx
1110XReserved, do not program.
111X0
11111PIA27-20 in
Asynchronous Serial Communications
Interface (ASCI)
The ASCI logic provides two individual full-duplex UARTs.
Each channel includes a programmable baud rate generator and modem control signals. The ASCI channels can
also support a multiprocessor communications format. For
ASCI0, up to three modem control signals and one clock
signal can be pinned out, while ASCI1 has a data-only
interface.
The receiver includes a 4-byte FIFO, plus a shift register as
shown in Figure 22.
DMA request signals between the various cells are handled
internally by the mechanisms described in this section,
and are not pinned-out, nor are the TEND termination
count outputs of the DMA channels.
DM1-0DAR18-16Destination
11000ext (TOUT/DREQ)
11001ASCI0 Tx
11010ASCI1 Tx
11011EMSCC Tx
1110XReserved, do not program.
111X0
11111PIA27-20 out
During Reset and in I/O Stop state, and for ASCI0 if /DCD0
is auto-enabled and is High, an ASCI is forced to the
following conditions:
■FIFO Empty
■All Error Bits Cleared (including those in the FIFO)
■Receive Enable Cleared (cntla bit 6 = 0)
■Transmit Enable Cleared (cntla bit 5 = 0).
If DCD is not auto-enabled, the /DCD pin has no effect on
the FIFOs or enable bits.
DS971850301
Overrun
Error
Error
Latches
4x4 Bit
Error
FIFO
P F O B
E E R K
ErrorShift Register
MP
Bit
4-Byte
Data FIFO
Figure 22. ASCI Receiver
Notes:
PE = Parity Error
FE = Framing Error
OR = Overrun
BK = Break
MP = Multiprocessor Bit
RXA
29
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