7220 datasheet(68/303 Pages) RENESAS

68 / 303 page

2-41

7220 Group User’s Manual

FUNCTIONAL DESCRIPTION

2.7 Serial I/O

Fig. 2.7.1 Serial I/O block diagram

Fig. 2.7.2 Serial I/O mode register (address 00DC16)

Serial I/O shift register (8)

Data bus

Serial I/O interrupt

request

Selection gate :

Connected to black

side at reset.

Synchronous circuit

Frequency

divider

1/8

1/4

1/16

SM1

SM0

Serial I/O counter (8)

SM5 : LSB

MSB

SM2

1/2

SM6

XIN

P22/SIN

P21/SOUT

P20/SCLK

1/2

SM3

P21 latch

P20 latch

SM3

(Address 00DD16)

SM : Serial I/O mode register

Clock source

generating circuit

Note: When the data is set in the serial I/O register (address 00DD16),

the register functions as the serial I/O shift register.

b7 b6 b5 b4 b3 b2 b1 b0

Serial I/O mode register (SM) [Address 00DC16]

Name

Functions

After reset RW

Serial I/O Mode Register

0, 1 Internal synchronous

clock selection bits

(SM0, SM1)

b1 b0

0: f(XIN)/4

1: f(XIN)/16

0: f(XIN)/32

1: f(XIN)/64

Synchronous clock

selection bit (SM2)

Serial I/O port

selection bit (SM3)

Transfer direction

selection bit (SM5)

0: P20, P21 functions

as port

1: SCLK, SOUT

0: External clock

1: Internal clock

0: LSB first

1: MSB first

Nothing is assigned. This bit is a write disable bit.

When this bit is read out, the value is “0.”

Fix this bit to “0.”

Serial input pin

selection bit (SM6)

0: Input signal from S IN pin

1: Input signal from S OUT pin

R—

7220 датащи(PDF) 68 Page - Renesas Technology Corp

7220 датащи(HTML) 68 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL