Intel 8XC196NT, User Manual

Page: 210 / 597

8-15
SYNCHRONOUS SERIAL I/O (SSIO) PORT
8.7 PROGRAMMING EXAMPLE
This code example configures SSIO0 as a master transmitter to send one byte of data to SSIO1,
the slave receiver. First it sets up a window to allow direct access to the necessary registers. Next,
it configures the clock and data pins. Since SSIO0 is sending data, SC0 (P6.4) and SD0 (P6.5) are
configured as special-function complementary outputs. Since SSIO1 is receiving data, SC1
(P6.6) and SD1 (P6.7) are configured as special-function inputs. The example also sets up a reg-
ister (result) to store the received data byte.
wsr equ 014h:byte
p6_dir equ 0d3h:byte ;window to 1fd3h
p6_mode equ 0d1h:byte ;window to 1fd1h
p6_reg equ 0d5h:byte ;window to 1fd5h
ssio_baud equ 0b4h:byte ;window to 1fb4h
ssio0_con equ 0b1h:byte ;window to 1fb1h
ssio1_con equ 0b3h:byte ;window to 1fb3h
ssio0_buf equ 0b0h:byte ;window to 1fb0h
ssio1_buf equ 0b2h:byte ;window to 1fb2h
result equ 122h:byte ;register to store the received data byte
cseg at 0ff2080h
ldb wsr,#1fh ;select window 1fh
ldb p6_dir,#0c0h ;set up SD1/SC1 as inputs and
;set up SD0/SC0 as complementary outputs
ldb p6_mode,#0f0h ;set up SD1/SC1, SD0/SC0 as special-function
ldb p6_reg,#0c0h ;set up SD1/SC1 inputs (1), SD0/SC0 outputs (0)
ldb ssio_baud,#80h ;enable baud-rate generator at 2 MHz
ldb ssio0_con,#0c9h ;set up channel 0 as master transmitter
ldb ssio1_con,#08h ;set up channel 1 as slave receiver
ldb ssio0_buf,#55h ;transmit data 55h
d_wait:
jbc ssio1_con,0,d_wait ;wait for data to be received
stb ssio1_buf,result ;store received data in “result”
sjmp $
end