Zilog Z16C35 Bedienungsanleitung PDF herunterladen (Seite 192)

Application Note

The Z180™ Interfaced with the SCC at MHZ

7-15

I/O Read Cycle

These tables show that a delay of the falling edge of /RD

satisfies the SCC TsA(RD) timing requirement of 50 ns

min. The Z180 calculated value is 30 ns min for the worst

case. Also, Z180 timing specification tAH (Address Hold

time) is 10 ns min. The SCC timing parameters ThA(RD)

{Address to /RD High Hold} and ThCE(RD) {/CE to /RD

High Hold} are minimum at 0 ns. The rising edge of /RD is

early to guarantee these parameters when considering

address decoders and gate propagation delays.

I/O Write Cycle

Delay the falling edge of /WR to satisfy the SCC TsA(/WR)

timing requirement of 50 ns min. The Z180 calculates 30

ns min worst case. Further, the Z180 timing specifications

tAH (Address Hold time) and tWDH (/WR high to data hold

time) are both 10 ns min. The SCC timing parameters

ThA(WR) {Address to /WR High Hold}, ThCE(WR) {/CE to

/WR High Hold} and TdWR(W) {Write data to /WR High

hold} are a minimum of 0 ns. The rising edge of /WR is

early to guarantee these parameter requirements.

This circuit depicts logic for the I/O interface and the

Interrupt Acknowledge Interface for 10 MHz clock of

operation. Figure 13 is the I/O read/write timing chart

(discussions of timing considerations on the Interrupt

Acknowledge cycle and the circuit using EPLD occur

later).

Table 8. Parameter Equations Worst Case (Without Delay Signals - No Wait State)

SCC

Parameters

Z180

Equation Value Units

TsA(RD) tcyc-tAD+tRDD1 30 min ns

TdA(DR) 3tcyc+tCHW+tcf-tAD-tDRS 245 min ns

TdRDf(DR) 2tcyc+tCHW+tcf-tRDD1-tDRS 160 min ns

TwRDI 2tcyc+tCHW+tcf-tDRS+tRDD2 185 min ns

TsA(WR) tcyc-tAD+tWRD1 30 min ns

TsDW(WR) tWDS 15 min ns

TwWRI tWRP 210 min ns

Table 9. Parameter Equations

Z180

Parameters

SCC

Equation Value Units

tDRS Address

3tcyc+tCHW-tAD-TdA(DR) 241 min ns

2tcyc+tCHW-tRDD1-TdRD(DR) 184 min ns

Page 186 of 316

UM011002-0808

1 2 ... 187 188 189 190 191 192 193 194 195 196 197 ... 321 322

Kommentare zu diesen Handbüchern

Keine Kommentare

Zilog Z16C35 Bedienungsanleitung Seite 192

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Sensoren Zilog Z16C35