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Programmable reload timer (prt), Figure 62. csi/o receive timing–external clock, Prt block diagram – Zilog Z80180 User Manual

Page 171

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Z8018x

Family MPU User Manual

156

UM005003-0703

Figure 62. CSI/O Receive Timing–External Clock

Programmable Reload Timer (PRT)

The Z8X180 contains a two channel 16-bit Programmable Reload Timer.
Each PRT channel contains a 16-bit down counter and a 16-bit reload
register. The down counter is directly read and written and a down counter
overflow interrupt can be programmably enabled or disabled. Also, PRT
channel 1 features a TOUT output pin (multiplexed with A18) which can be
set High, Low, or toggled. Thus, PRT1 can perform programmable output
waveform generation.

PRT Block Diagram

The PRT block diagram is depicted in Figure 63. The two channels
feature separate timer data and reload registers and a common status/

CKS

RXS

RE

EF

Read or write of CSI/O

Transmit/Receive

Data Register

11.5

f

Sampling

LSB

MSB

11.5

f

11.5

f

11.5

f

16.5

f

16.5

f

16.5

f

16.5

f

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