NEC Network Controller uPD98502 - Manual (Page 425)

CHAPTER 9 TIMER
Preliminary User’s Manual S15543EJ1V0UM 425
9.3 Registers
9.3.1 Register map
Offset Address Register Name R/W Access Description
1000_00B0H TMMR R/W W/H/B Timer Mode Register
1000_00B4H TM0CSR R/W W/H/B Timer CH0 Count Set Register
1000_00B8H TM1CSR R/W W/H/B Timer CH1 Count Set Register
1000_00BCH TM0CCR R W/H/B Timer CH0 Current Count Register
1000_00C0H TM1CCR R W/H/B Timer CH1 Current Count Register
Remarks 1. In the “R/W” field,
“W” means “writeable”,
“R” means “readable”,
“RC” means “read-cleared”,
“- “ means “not accessible”.
2. All internal registers are 32-bit word-aligned registers.
3. The burst access to the internal register is prohibited.
If such burst access has been occurred, IRERR bit in NSR is set and NMI will assert to CPU.
4. Read access to the reserved area will set the CBERR bit in the NSR register and the dummy read
response data with the data-error bit set on SysCMD [0] is returned.
5. Write access to the reserved area will set the CBERR bit in the NSR register, and the write data is lost.
6. In the “Access” filed,
“W” means that word access is valid,
“H” means that half word access is valid,
“B” means that byte access is valid.
7. Write access to the read-only register cause no error, but the write data is lost.
8. The CPU can access all internal registers, but IBUS master device cannot access them.
9.3.2 TMMR (Timer Mode Register)
The Timer Mode Register “TMMR” is a read-write and 32-bit word-aligned register. TMMR is used to control the
timer. TMMR is initialized to 0 at reset and contains the following fields:
Bits Field R/W Default Description
31:9 Reserved R/W 0 Hardwired to 0.
8 TM1EN R/W 0 Timer CH1 enable:
1 = Enable, starts the timer CH1
(Automatically reloads the original timer value and starts if timer had expired)
0 = Disable, stops the timer
7:1 Reserved R/W 0 Hardwired to 0.
0 TM0EN R/W 0 Timer CH0 enable:
1 = Enable, starts the timer CH0
(Automatically reloads the original timer value and starts if timer had expired)
0 = Disable, stops the timer