TDA8005 Datasheet, PDF (13/32 Pages) NXP Semiconductors – Low-power smart card coupler

Philips Semiconductors
Low-power smart card coupler
Product specification
TDA8005
USE OF PERIPHERAL INTERFACE
Write operation:
Select the correct register with R/W, REG0, REG1.
Write the word in the peripheral shift register (PSR) with
DATA and STROBE. DATA is shifted on the rising edge
of STROBE. 8 shifts are necessary.
Give a negative pulse on ENABLE. The data is parallel
loaded in the register on the falling edge of ENABLE.
Read operation:
Select the correct register with R/W, REG0 and REG1.
Give a first negative pulse on ENABLE. The word is
parallel loaded in the peripheral shift register on the
rising edge of ENABLE.
Give a second negative pulse on ENABLE for
configuring the PSR in shift right mode.
Read the word from PSR with DATA and STROBE.
DATA is shifted on the rising edge of STROBE. 7 shifts
are necessary.
Table 3 Example of peripheral interface
CHANGE OF CLOCK CONFIGURATION⁽¹⁾
LOOP
CLR REG0
CLR REG1
CLR R/W
MOV R2, #8
RRC A
MOV DATA C
CLR STROBE
SET STROBE
DJNZ R2, LOOP
CLR ENABLE
SET ENABLE
SET DATA
RET
READ CHARACTER ARRIVED IN UART RECEIVE⁽²⁾
CLR REG0
CLR REG1
SET R/W
CLR ENABLE
SET ENABLE
CLR ENABLE
SET ENABLE
MOV R2, #8
LOOP
MOV C, DATA
RRC A
CLR STROBE
SET STROBE
DJNZ R2, LOOP
SET DATA
RET
Notes
1. The new configuration is supposed to be in the accumulator.
2. The character will be in the accumulator.
1996 Sep 25
13