Owner's manual

DS782F2 27
CS4349
6.3.2 SPI Read
To read from the device, follow the procedure below while adhering to the values specified in ”Switching
Characteristics - Control Port - SPI Format” on page 15.
1. Bring CS
low.
2. The address byte on the CDIN pin must then be 10011111 (R/W
=1).
3. CDOUT pin will then output the data from the register pointed to by the MAP, which is set during the
SPI write operation.
4. If the INCR bit (see Section 6.1) is set to 1, keep CS
low and continue providing clocks on CCLK to
read from multiple consecutive registers. Bring CS
high when reading is complete.
5. If the INCR bit is set to 0 and further SPI reads from other registers are desired, it is necessary to bring
CS
high, and follow the procedure detailed from step 1. If no further reads from other registers are
desired, bring CS
high.
6.4 Memory Address Pointer (MAP)
6.4.1 INCR (Auto Map Increment Enable)
Default = ‘0’
0 - Disabled
1 - Enabled
6.4.2 MAP (Memory Address Pointer)
Default = ‘0000’
76543210
INCR Reserved Reserved Reserved MAP3 MAP2 MAP1 MAP0
00000000
MAP
MSB
LSB
DATA
byte 1
byte n
R/W
R/W
ADDRESS
CHIP
ADDRESS
CHIP
MSB
LSB
MSB
LSB
MAP = Memory Address Pointer, 8 bits, MSB first
High Impedance
1001111 1001111
CCLK
CDIN
CDOUT
CS
Figure 19. Control Port Timing, SPI Mode