89C5121-SK1 Atmel, 89C5121-SK1 Datasheet - Page 79

• Manufacturer Part Number: 89C5121-SK1
• Description: KIT SMART CARD FOR AT89C5121
• Manufacturer: Atmel
• Type: Smart Cardr

Specifications of 89C5121-SK1

• Contents: Board
• For Use With/related Products: AT89C5121
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: T89C5121-SK1; T89C5121-SK1

Table 56. TMOD Register
TMOD (S:89h) - Timer 0/Counter Mode Control Registers
Reset Value = 0000 0000b
4164G–SCR–07/06
Bit Number
GATE1
7
6
5
4
3
2
1
0
7
Bit Mnemonic
GATE1
GATE0
C/T1#
C/T0#
M01
M10
M00
M11
C/T1#
6
Description
Timer 1 Gating Control bit
Clear to enable Timer 1 whenever TR1 bit is set.
Set to enable Timer 1 only while INT1 pin is high and TR1 bit is set.
Timer 1 Counter/Timer 0 Select bit
Clear for Timer 0 operation: Timer 1 counts the divided-down system clock.
Set for Counter operation: Timer 1 counts negative transitions on external pin T1.
Timer 1 Mode Select bits
M11
Timer 0 Gating Control bit
Clear to enable Timer 0 whenever TR0 bit is set.
Set to enable Timer 0/Counter 0 only while INT0 pin is high and TR0 bit is set.
Timer 0 Counter/Timer 0 Select bit
Clear for Timer 0 operation: Timer 0 counts the divided-down system clock.
Set for Counter operation: Timer 0 counts negative transitions on external pin T0.
Timer 0 Mode Select bit
M10
TH0 is an 8-bit Timer 0 using Timer 1’s TR0 and TF0 bits.
0
0
1
1
0
0
1
1
M00
0
1
0
1
0
1
M01
0
1
M11
5
Mode 0:8-bit Timer 0/Counter (TH0) with 5-bit prescaler (TL0).
Mode 1:16-bit Timer 0/Counter
Mode 2:8-bit auto-reload Timer 0/Counter (TL0). Reloaded from TH0 at overflow.
Mode 3:TL0 is an 8-bit Timer 0/Counter.
Operating mode
Operating mode
Mode 0:8-bit Timer 0/Counter (TH1) with 5-bit prescaler (TL1).
Mode 1:16-bit Timer 0/Counter.
Mode 2:8-bit auto-reload Timer 0/Counter (TL1). Reloaded from TH1 at overflow.
Mode 3:Timer 1 halted. Retains count.
M01
4
GATE0
3
C/T0#
2
M10
1
A/T8xC5121
M00
0
79