EZ80L92MCU Datasheet, PDF (140/241 Pages) Zilog, Inc. – eZ80Acclaim Flash Microcontrollers

eZ80L92 MCU
Product Specification
125
Table 66. GPIO Mode Selection when using the IrDA Encoder/Decoder
GPIO Port D Bits
PD0
PD1
PD2–PD7
Allowable GPIO
Port Mode
7
7
Any other than GPIO Mode 7
(1, 2, 3, 4, 5, 6, 8, or 9)
Allowable Port Mode Functions
Alternate Function
Alternate Function
Output, Input, Open-Drain, Open-Source,
Level-sensitive Interrupt Input, or Edge-
Triggered Interrupt Input
Loopback Testing
Both internal and external loopback testing can be accomplished with the endec on the
eZ80L92. Internal loopback testing is enabled by setting the LOOP_BACK bit to 1. Dur-
ing internal loopback, IR_TXD output signal is inverted and connected on-chip to the IR_RXD
input. External loopback testing of the off-chip IrDA transceiver may be accomplished by
transmitting data from the UART while the receiver is enabled (IR_RXEN set to 1).
Infrared Encoder/Decoder Register
After a RESET, the infrared encoder/decoder register is set to its default value. Any Writes
to unused register bits are ignored and Reads return a value of 0. Unused bits within a reg-
ister must always be written with a value of 0. The IR_CTL register is described in Table
67.
Table 67. Infrared Encoder/Decoder Control Register (IR_CTL = 00BFh)
Bit
7
6
Reset
0
0
CPU Access
R/W R/W
Note: R = Read only; R/W = Read/Write.
5
0
R/W
4
0
R/W
3
0
R/W
2
0
R/W
1
0
R/W
0
0
R/W
Bit
Position
Value Description
[7:3]
000000 Reserved.
2
0
LOOP_BACK ₁
Internal LOOP BACK mode is disabled.
Internal LOOP BACK mode is enabled.
IR_TXD output is inverted and connected to IR_RXD input for
internal loop back testing.
1
0
IR_RXEN
1
IR_RXD data is ignored.
IR_RXD data is passed to UART0 RxD.
PS013012-1004
PRELIMINARY
Infrared Encoder/Decoder