Z8523008PSG Zilog, Z8523008PSG Datasheet - Page 106

• Manufacturer Part Number: Z8523008PSG
• Description: IC 8MHZ ESCC 40-DIP
• Manufacturer: Zilog

Specifications of Z8523008PSG

• Controller Type: Serial Communications Controller (SCC)
• Interface: Bus
• Voltage - Supply: 4.5 V ~ 5.5 V
• Current - Supply: 4mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.620", 15.75mm)
• Operating Supply Voltage: 5 V
• Supply Current (max): 9 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 269-3917; Z8523008PSG

PS005303-0907
RTS Problem Solutions
Automatic TxD Forced High Problem Description
2. Enable the CRC/Flag on Underrun (WR10 bit 2 equals 0).
3. Issue a
The
consecutive frames back-to-back. This command does not work with more than two back-
to-back frames.
In the latter condition, if the
Transmit Underrun
ing flag is sent. The final frame is not concluded, and is corrupted.
A workaround for the RTS problem is not to send back-to-back frames. Idle time is
inserted between frames.
There is, however, a limitation to this workaround in that the system throughput is reduced
by the idle time inserted between the frames.
Figure 36
If WR10 is programmed with bits 6 and 5 equal to 01 (NRZI), bit 3 equals 1 (Mark Idle)
and WR4 bits 5 and 4 equal 10 (SDLC), the TxD pin is forced High after detecting the last
bit of the closing flag at the falling edge of TxC. This feature does not work if back-to-
deactivates automatically after the closing flag disappears.
Automatic RTS Deactivation
RTS
RTS
TxD
TxD
illustrates Automatic RTS Deactivation.
Deactivate RTS
RTS deactivates too soon, after the CRC, but before the closing
flag if more than two back-to-back frames are sent.
Flag Frame n-1 CRC
Flag Frame n-1 CRC
Figure 36. Automatic RTS Deactivation
RTS deactivates correctly (after the closing flag)
if only one back-to-back frame is sent.
Frame n-1
Frame n-1
ISR. RTS is deactivated after the CRC is gone, but before the clos-
Deactivate RTS
command in the Transmit Underrun ISR. The RTS signal
Flag Frame n
Flag Frame n
command works for a single frame and for two
Frame n
command is issued at the beginning of the
Frame n
CRC Flag
CRC Flag
Product Specification
Z80230/Z85230 Errata
RTS must deactivate
after the last closing
flag is gone.
Z85230/Z80230
101