TL16PNP550A_08 Datasheet, PDF (19/40 Pages) Texas Instruments – ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH PLUG-AND-PLAY (PnP) AND AUTOFLOW CONTROL

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TL16PNP550A
ASYNCHRONOUS COMMUNICATIONS ELEMENT
WITH PLUGĆANDĆPLAY (PnP) AND AUTOFLOW CONTROL
SLLS190B − MARCH 1995 − REVISED MARCH 1996
PRINCIPLES OF OPERATION
The TL16PNP550A architecture (see functional block diagram) has been designed, so that it can be configured
in various operational modes. These modes are described in the Table 1.
Table 1. TL16PNP550A Operational Modes^†
MODE DESCRIPTION
UARTBYPASS PNPBYPASS ICONFIG<3:0> ACONFIG <1:0>
TERMINAL
TERMINAL
TERMINAL
TERMINAL
PnP controller and logical device (ACE)
0
1
X
X
Stand-alone PnP Controller
1
1
X
X
ACE TL16C550C only
0
0
Active
Active
Manufacturer test mode^‡
1
0
X
X
† _{X = irrelevant, 0 = low level, 1 = high level}
‡ _{During manufacturer test mode, the oscillator clock is disabled. This mode is used by the manufacturer for test only.}
Connecting the PNPBYPASS terminal to V_CC enables the PnP autoconfiguration sequence. When PnP is
enabled, the ACONFIG<1:0> and ICONFIG<3:0> are irrelevant and should be tied to GND or V_CC.
In the stand-alone PnP controller mode, the controller responds to the autoconfiguration sequence and supports
one logical device, one I/O address, one interrupt, and no DMA. The address decoder only decodes eight
contiguous locations. During this mode, the UART is disabled and CS and EXINTR terminals become active.
The UART input terminals should be tied to either V_CC or GND to avoid floating input terminals.
When PnP is disabled or bypassed, the PNPBYPASS terminal is tied to GND and the configuration in Table 2
applies.
Table 2. PnP Disabled or Bypassed Configuration
ACONFIG<1:0>
00
01
10
11
COM
COM1
COM2
COM3
COM4
I/O BASE ADDRESS
3F8 −3FF
2F8 −2FF
3E8 −3EF
2E8 −2EF
The decimal value X of ICONFIG<3:0> content enables the corresponding IRQx. For example,
ICONFIG<3:0> = 0011 enables IRQ3 (Table 3).
ICONFIG
0000
0001
0010
0011
0100
0101
0110
0111
Table 3. ICONFIG to IRQx
IRQx
N/A
N/A
N/A
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
ICONFIG
1000
1001
1010
1011
1100
1101
1110
1111
IRQx
N/A
IRQ9
IRQ10
IRQ11
IRQ12
N/A
N/A
IRQ15
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