PC87393 datasheet(131/148 Pages) NSC

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8.0 Legacy Functional Blocks (Continued)

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8.4

IR FUNCTIONALITY (SP2)

8.4.1

General Description

This section describes the IR support registers of Serial Port 2 (SP2). The UART support registers for both SP1 and SP2

are described in Section 8.3.

The IR functional block provides advanced, versatile serial communications features with IR capabilities.

SP2 supports also two DMA channels; the functional block can use either one or both of them. One channel is required for

IR-based applications, since IR communication works in half duplex fashion. Two channels would normally be needed to

handle high-speed full duplex UART based applications.

8.4.2

IR Mode Register Bank Overview

Eight register banks, each containing eight registers, control SP2 operation. Banks 0-3 are used to control both UART and

IR modes of operation; banks 4-7 are used to control and configure the IR modes of operation only. All registers use the

same 8-byte address space to indicate offsets 00h through 07h. The BSR register selects the active bank and is common

to all banks. See Figure 31.

Figure 31. SP2 Register Bank Architecture

BANK 0

BANK 1

BANK 2

BANK 3

BANK 4

BANK 5

BANK 6

BANK 7

Offset 07h

Offset 06h

Offset 05h

Offset 04h

LCR/BSR

Offset 02h

Offset 01h

Offset 00h

Common

Throughout

All Banks

IR Special Banks

(Banks 4-7)

PC87393 Datasheet(PDF) 131 Page - National Semiconductor (TI)