Z16M1720ASG1868 Zilog, Z16M1720ASG1868 Datasheet - Page 254

• Manufacturer Part Number: Z16M1720ASG1868
• Description: IC PCMCIA INTERFACE 100-VQFP
• Manufacturer: Zilog

Specifications of Z16M1720ASG1868

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 100-LQFP
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

234
Table 4. Asynchronous Mode (Continued)
UM008101-0601
Function
Idle Mode
Data transfer and
error monitoring
<   % 2 7 2 G T K R J G T C N U
7 U G T / C P W C N
WR5
WR0
WR1
Typical Program Steps
Request to send, transmit enable, transmit
character length, data terminal ready
Pointer 1, Reset External/Status Interrupt
Transmit Interrupt Enable, Status Affects
Vector,
Interrupt on all Receive characters. Disable
Wait/Ready function, External Interrupt Enable
Transfer first data byte to SIO
Execute Halt Instruction or other program
Z80 Interrupt Acknowledge cycle transfers
RR2 to CPU
If a character is received:
• Transfer data character to CPU
• Update pointers and parameters
• Return from Interrupt
If transmitter buffer is empty:
• Transfer data character to SIO
• Update pointers and parameters
• Return from interrupt
Comments
Receive and Transmit both
fully initialized. Auto Enables
enables transmitter if CTS is
active and receiver if DCD is
active
Transmit/receive Interrupt
Mode Selected.
External Interrupt monitors the
status of the CTS, DCD, and
SYNC inputs and detects the
Break sequence. Status affects
Vector In Channel B only. This
data byte must be transferred or
no transmit interrupts occur.
Program is waiting for an
interrupt from the SIO
When the interrupt occurs, the
interrupt vector is modified by:
1) Receive character available;
2) Transmit buffer empty;
3) External/status change; and
4) Special receive condition.
Program control is transferred
to one of the eight Interrupt
Service routines.
Serial Input/Output