IBM EM78P312N manual Timer/Counter, Bit Microcontroller

EM78P312N

8-Bit Microcontroller

of the TC3 pin input, the contents of the counter are loaded into TCR3A, counter is cleared and interrupt is generated again. If an overflow before the edge is detected, the FFH is loaded into TCR3DA and an overflow interrupt is generated. During interrupt processing, it can be determined whether or not there is an overflow by checking whether the TCR3DA value is FFH. After an interrupt (capture to TCR3DA or overflow detection) is generated, capture and overflow detection are halted until TCR3DA is read out.

Source Clock

Up-counter K-2K-1

K 0 1

m-1 m

m+1

n-1

n 0 1 2

3

FE FF0 1

2 3

TC3 Pin Input

TCR3DA

K

n

FF (Overflow)

TCR3DB

m

FE

TC3 Interrupt

Capture

Capture

Overflow

Reading TCR3DA

Fig. 5-23 Timing Chart of Capture Mode

5.11 Timer/Counter 4

Registers for Timer 4 Circuit

R_BANK

Address

Name

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Bank 0

0X0B

TC4CR

TC4FF1

TC4FF0

TC4S

TC4CK2

TC4CK1

TC4CK0

TC4M1

TC4M0

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Bank 0

0X0C

TC4D

TC4D7

TC4D6

TC4D5

TC4D4

TC4D3

TC4D2

TC4D1

TC4D0

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Bank 0

0x0E

ISFR1

EXIF5

TCIF2

ADIF

0

EXIF3

TCIF4

SPIF

TCIF3

R/W

R/W

--

R/W

R/W

R/W

R/W

R/W

SFR

0x0E

IMR1

EXIE5

TCIE2

ADIE

0

EXIE3

TCIE4

SPIE

TCIE3

R/W

R/W

--

R/W

R/W

R/W

R/W

R/W

Product Specification (V1.0) 10.03.2006 • 39

(This specification is subject to change without further notice)