Z80382 Datasheet, PDF (41/77 Pages) Zilog, Inc. – HIGH-PERFORMANCE DATA COMMUNICATIONS PROCESSORS

Zilog
Z80382/Z8L382
High-Performance Data Communications Processors
Transmitter FIFO
On the 380C interface, the transmit FIFO can be pro-
The transmitter FIFO is 16-bytes deep with Host write and grammed to interrupt the 380C on 1, 4, 8 or 14 bytes of
1 ^{380C read access. In FIFO mode, the Host will receive an available data. A timeout feature exists, Transmitter Time-}
interrupt when the transmitter FIFO becomes empty. The out Timer, which is an additional 8-bit timer with the BRG
interrupt is cleared when the transmitter FIFO becomes as the input source. If the transmitter FIFO is non-empty
non-empty or the IIR register is read by the Host.
and no Host write or 380C read of the FIFO has taken
place within the timer interval, a timeout will occur, causing
a corresponding interrupt to the 380C.
MPU
Control
Line
Internal Clock
Sync
MPU Databus
(MPU Side
8
Read)
FIFO Control ₅
Register
MPU IRQ
Read
Pointer
16X8
Data Bits
ALU
Internal Clock
Sync
PC
Control
Line
8
Write
Pointer
PC Databus
(PC Side
Write)
Internal
Clock
PC IRQ
Figure 25. 16550 Mimic Transmitter FIFO Block Diagram
Transmit And Receive Timers
Because of the speed at which data transfers can take
place between the Z382 and the Host, two timers have
been added to alleviate any software problems that a high
speed data transfer might cause. These timers allow the
programmer to slow down the data transfer to simulate the
Mimic receiving and transmitting the data serially. The tim-
ers receive their input from the Mimic BRG clock. This al-
lows the programmer access to a 24-bit timer to slow down
the data transfers.
Mimic Programming Registers
The Mimic module contains a set of registers for program-
ming various aspects of Mimic operation. These are:
Register
Mimic Master Control Register
Mimic DMA Control Register
Mimic IUS/IP Register
Interrupt Enable Register
Interrupt Vector Register
FIFO Status and Control Register
Rx Timeout Time Constant Register
Tx Timeout Time Constant Register
Transmitter Time Constant Register
Receiver Time Constant Register
380C I/O
Address
%00FF
%00EF
%00FE
%00FD
%00FC
%00EC
%00EA
%00EB
%00FA
%00FB
DS97Z382000
PRELIMINARY
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